SEC Petition Evaluation Report

Petition SEC-00216 

Report Rev #:0 Report Submittal Date: January 29, 2015 

Subject Expert(s): Monica Harrison-Maples

Site Expert(s): N/A

Petition Administrative Summary

Petition Under Evaluation

Petition # Petition Type Petition Receipt Date Qualification Date DOE/AWE Facility Name

SEC-00216 83.13 June 12, 2014 August 5, 2014 Dow Chemical Company

Petitioner-Requested Class Definition

All employees in all areas who worked for Dow Chemical Co. in Pittsburg, CA (aka Walnut Creek, CA), from 

1947-1957.

Class Evaluated by NIOSH

All employees who worked in any area of the Dow Chemical Company facility in Pittsburg, California, from 

January 1, 1947 through December 31, 1957.

NIOSH-Proposed Class to be Added to the SEC

All Atomic Weapons Employer employees who worked for Dow Chemical Company in Pittsburg, California,

from October 1, 1947 through June 30, 1957, for a number of work days aggregating at least 250 work days, 

occurring either solely under this employment or in combination with work days within the parameters 

established for one or more other classes of employees included in the Special Exposure Cohort.

Related Petition Summary Information 

SEC Petition Tracking #(s) Petition Type DOE/AWE Facility Name Petition Status

N/A N/A N/A N/A

Related Evaluation Report Information 

Report Title DOE/AWE Facility Name

N/A N/A

ORAU Lead Technical Evaluator: Monica 

Harrison-Maples

ORAU Peer Review Completed By: Daniel H. Stempfley

Peer Review Completed By: [Signature on File] 1/29/2015

Lara Hughes Date

[Signature on File] 1/29/2015 SEC Petition Evaluation Reviewed By:

J. W. Neton Date

[Signature on File] 1/30/2015 SEC Evaluation Approved By:

Stuart L. Hinnefeld Date
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Evaluation Report Summary: SEC-00216, Dow Chemical Company

This evaluation report by the National Institute for Occupational Safety and Health (NIOSH)

addresses a class of employees proposed for addition to the Special Exposure Cohort (SEC) per the

Energy Employees Occupational Illness Compensation Program Act of 2000, as amended, 42 U.S.C.

§ 7384 et seq. (EEOICPA) and 42 C.F.R. pt. 83, Procedures for Designating Classes of Employees as 

Members of the Special Exposure Cohort under the Energy Employees Occupational Illness 

Compensation Program Act of 2000.

Petitioner-Requested Class Definition

Petition SEC-00216 was received on June 12, 2014, and qualified on August 5, 2014. The petitioner 

requested that NIOSH consider the following class: All employees in all areas who worked for Dow 

Chemical Co. in Pittsburg, CA (aka Walnut Creek, CA), from 1947-1957.

Class Evaluated by NIOSH

Based on its preliminary research, NIOSH accepted the petitioner-requested class. NIOSH evaluated 

the following class: All employees who worked in any area of the Dow Chemical Company facility in 

Pittsburg, California, from January 1, 1947 through December 31, 1957.

NIOSH-Proposed Class to be Added to the SEC

Based on its full research of the class under evaluation, NIOSH has defined a single class of 

employees for which NIOSH cannot estimate radiation doses with sufficient accuracy. The NIOSHproposed class includes all Atomic Weapons Employer employees who worked for Dow Chemical 

Company in Pittsburg, California, from October 1, 1947 through June 30, 1957, for a number of work 

days aggregating at least 250 work days, occurring either solely under this employment or in 

combination with work days within the parameters established for one or more other classes of 

employees included in the Special Exposure Cohort. The class under evaluation was modified (see 

Section 3.0 below) because records of the contract and a memorandum documenting the conclusion of 

the work by Dow Chemical Company provide the start and end dates for the Atomic Energy 

Commission (AEC) work. The periods from January 1, 1947 through September 30, 1947, and from 

July 1, 1957 through December 31, 1957, have been excluded from the NIOSH-proposed class 

because covered work was not performed during these times.

Feasibility of Dose Reconstruction

Per EEOICPA and 42 C.F.R. § 83.13(c)(1), NIOSH has established that it does not have access to 

sufficient information to: (1) estimate the maximum radiation dose, for every type of cancer for which 

radiation doses are reconstructed, that could have been incurred in plausible circumstances by any 

member of the class; or (2) estimate radiation doses of members of the class more precisely than an 

estimate of maximum dose. Information available from the site profile and additional resources is not 

sufficient to document or estimate the maximum internal and external potential exposure to members 

of the proposed class under plausible circumstances during the specified period.
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The NIOSH dose reconstruction feasibility findings are based on the following:

• Principal sources of internal radiation for members of the proposed class included exposures to

uranium contained in phosphate ores commercially processed to manufacture phosphate fertilizers 

and phosphate chemicals. The byproduct phosphatic acid derived from these manufacturing 

processes was used as a starting point for investigations into chemical recovery of the uranium 

naturally contained in the phosphate ores. NIOSH estimates between 17,000-26,500 gallons of 

solution were analyzed over the nine-and-one-half years of AEC research operations at Dow. The 

modes of potential exposure were inhalation and ingestion of uranium and its progeny during wet 

chemistry separation work, including evaporation and condensation operations to perform sample 

analyses.

• NIOSH has not located documentation giving any indication of a routine internal personnel 

exposure monitoring program for the period under evaluation. No internal monitoring or air 

sample data have been located by NIOSH. Without additional personnel radiation monitoring data 

representing the period from October 1, 1947 through June 30, 1957, NIOSH has insufficient 

information to appropriately characterize radioactive material intakes during Dow Chemical 

Company operations.

• Although the uranium content of the phosphate rock, from which this acid derived its uranium, 

was very low, the uranium concentration process developed at Dow resulted in refined uranium 

products. The concentration of uranium in the acids involved in the research at Dow Chemical 

Company labs is not documented in available reports for the period under evaluation. The 

documentation does not provide indication of the concentration or the total quantity of uranium in 

the purified products either. Without monitoring information or quantitative source term 

information, NIOSH cannot put an upper bounding estimate on potential exposures with any 

degree of confidence.

• Principal sources of external radiation for members of the proposed class included exposures to 

natural uranium and progeny during development of a wet-chemistry recovery process. Samples 

of uranium-bearing acids were treated and analyzed to develop procedures for the recovery of any 

uranium contained in these samples. Liquids were handled in hoods, using standard chemical 

protection methods and protective equipment.

• NIOSH has not located any indication of external personnel exposure monitoring for the period 

under evaluation. NIOSH’s research indicates personnel monitoring for external exposure to 

radiological materials was not performed. No records or documentation of any program for 

external dose monitoring have been located.

• NIOSH does not have access to sufficient personnel monitoring, workplace monitoring, or source 

term data to estimate unmonitored external exposures for Dow Chemical Company workers

exposed during the development of uranium-recovery operations from October 1, 1947 through 

June 30, 1957.

• Pursuant to 42 C.F.R. § 83.13(c)(1), NIOSH determined that there is insufficient information to 

either: (1) estimate the maximum radiation dose, for every type of cancer for which radiation 

doses are reconstructed, that could have been incurred under plausible circumstances by any 
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member of the class; or (2) estimate the radiation doses of members of the class more precisely 

than a maximum dose estimate.

• Although NIOSH found that it is not possible to completely reconstruct radiation doses for the 

proposed class, NIOSH intends to use any internal and external monitoring data that may become 

available for an individual claim (and that can be interpreted using existing NIOSH dose 

reconstruction processes or procedures). Therefore, dose reconstructions for individuals employed 

at Dow Chemical Company during the period from October 1, 1947 through June 30, 1957, but 

who do not qualify for inclusion in the SEC, may be performed using these data as appropriate.

• NIOSH finds that it is likely feasible to reconstruct occupational medical dose for Dow Chemical 

Company by using claimant-favorable assumptions and the Technical Information Bulletin, Dose 

Reconstruction from Occupational Medical X-Ray Procedures (ORAUT-OTIB-0006).

Health Endangerment Determination

Per EEOICPA and 42 C.F.R. § 83.13(c)(3), a health endangerment determination is required because 

NIOSH has determined that it does not have sufficient information to estimate dose for the members 

of the proposed class.

NIOSH did not identify any evidence supplied by the petitioners or from other resources that would 

establish that the proposed class was exposed to radiation during a discrete incident likely to have 

involved exceptionally high-level exposures. However, evidence indicates that some workers in the 

proposed class may have accumulated substantial chronic exposures through episodic intakes of 

radionuclides, combined with external exposures to gamma, beta, and neutron radiation. 

Consequently, NIOSH has determined that health was endangered for those workers covered by this 

evaluation who were employed for at least 250 aggregated work days either solely under this

employment or in combination with work days within the parameters established for one or more 

other SEC classes.
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Table of Contents

1.0 Purpose and Scope.......................................................................................................................... 9

2.0 Introduction .................................................................................................................................... 9

3.0 SEC-00216, Dow Chemical Company Class Definitions............................................................ 10

3.1 Petitioner-Requested Class Definition and Basis................................................................ 10

3.2 Class Evaluated by NIOSH ................................................................................................. 11

3.3 NIOSH-Proposed Class to be added to the SEC ................................................................. 11

4.0 Data Sources Reviewed by NIOSH to Evaluate the Class........................................................... 12

4.1 Site Profile Technical Basis Documents (TBDs)................................................................ 12

4.2 ORAU Technical Information Bulletins (OTIBs)............................................................... 12

4.3 Facility Employees and Experts.......................................................................................... 13

4.4 Previous Dose Reconstructions........................................................................................... 13

4.5 NIOSH Site Research Database .......................................................................................... 14

4.6 Documentation and/or Affidavits Provided by Petitioners ................................................. 14

5.0 Radiological Operations Relevant to the Class Evaluated by NIOSH......................................... 15

5.1 Dow Chemical Company Plant and Process Descriptions.................................................. 15

5.2 Radiological Exposure Sources from Dow Chemical Company Operations...................... 21

5.2.1 Internal Radiological Exposure Sources from Dow Chemical Company 

Operations................................................................................................................ 21

5.2.1.1 Uranium.................................................................................................... 21

5.2.1.2 Thorium.................................................................................................... 21

5.2.2 External Radiological Exposure Sources from Dow Chemical Company 

Operations................................................................................................................ 22

5.2.2.1 Photon....................................................................................................... 22

5.2.2.2 Beta........................................................................................................... 22

5.2.2.3 Neutron ..................................................................................................... 25

6.0 Summary of Available Monitoring Data for the Class Evaluated by NIOSH ............................. 25

6.1 Available Dow Chemical Company Internal Monitoring Data........................................... 25

6.2 Available Dow Chemical Company External Monitoring Data.......................................... 26

7.0 Feasibility of Dose Reconstruction for the Class Evaluated by NIOSH...................................... 26

7.1 Pedigree of Dow Chemical Company Data......................................................................... 27

7.1.1 Internal Monitoring Data Pedigree Review............................................................. 27

7.1.2 External Monitoring Data Pedigree Review............................................................ 27

7.2 Evaluation of Bounding Internal Radiation Doses at Dow Chemical Company ................ 27

7.2.1 Evaluation of Bounding Process-Related Internal Doses........................................ 27

7.2.1.1 Urinalysis Information and Available Data.............................................. 28

7.2.1.2 Lung Counting Information and Available Data...................................... 28

7.2.1.3 Other Types of Bioassay .......................................................................... 28

7.2.1.4 Airborne Levels........................................................................................ 28

7.2.2 Evaluation of Bounding Residual Period Internal Doses........................................ 28
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7.2.3 Methods for Bounding Internal Dose at Dow Chemical Company ........................ 29

7.2.4 Internal Dose Reconstruction Feasibility Conclusion ............................................. 29

7.3 Evaluation of Bounding External Radiation Doses at Dow Chemical Company ............... 30

7.3.1 Evaluation of Bounding Process-Related External Doses....................................... 30

7.3.2 Dow Chemical Company Occupational X-Ray Examinations ............................... 30

7.3.3 Methods for Bounding External Dose at Dow Chemical Company ....................... 30

7.3.4 External Dose Reconstruction Feasibility Conclusion............................................ 31

7.4 Evaluation of Petition Basis for SEC-00216....................................................................... 31

7.4.1 Inadequate Records ................................................................................................. 31

7.4.2 Surrogate Data ......................................................................................................... 32

7.4.3 DOE Radiological Survey ....................................................................................... 32

7.5 Other Potential SEC Issues Relevant to the Petition Identified During the Evaluation...... 33

7.6 Summary of Feasibility Findings for Petition SEC-00216.................................................. 34

8.0 Evaluation of Health Endangerment for Petition SEC-00216...................................................... 35

9.0 Class Conclusion for Petition SEC-00216 ................................................................................... 36

10.0 References .................................................................................................................................... 37

Attachment One: Data Capture Synopsis.............................................................................................. 41

Tables

Table 4-1: No. of Dow Chemical Company Claims Submitted Under the Dose 

Reconstruction Rule .............................................................................................................................. 14

Table 5-1: Beta and Gamma Emissions of Primary Interest ................................................................. 23

Table 7-1: Summary of Feasibility Findings for SEC-00216 ............................................................... 35
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SEC Petition Evaluation Report for SEC-00216

ATTRIBUTION AND ANNOTATION: This is a single-author document. All conclusions drawn from 

the data presented in this evaluation were made by the Oak Ridge Associated Universities (ORAU)

Team Lead Technical Evaluator: Monica Harrison-Maples, ORAU. The rationales for all 

conclusions in this document are explained in the associated text.

1.0 Purpose and Scope

This report evaluates the feasibility of reconstructing doses for all employees who worked in any area

of the Dow Chemical Company facility (often referred to as Dow in this report) in Pittsburg, 

California, from January 1, 1947 through December 31, 1957. It provides information and analyses 

germane to considering a petition for adding a class of employees to the congressionally-created SEC.

This report does not make any determinations concerning the feasibility of dose reconstruction that 

necessarily apply to any individual energy employee who might require a dose reconstruction from 

NIOSH. This report also does not contain the final determination as to whether the proposed class 

will be added to the SEC (see Section 2.0).

This evaluation was conducted in accordance with the requirements of EEOICPA, 42 C.F.R. pt. 83,

and the guidance contained in the Division of Compensation Analysis and Support’s (DCAS) Internal 

Procedures for the Evaluation of Special Exposure Cohort Petitions, DCAS-PR-004.1

2.0 Introduction

Both EEOICPA and 42 C.F.R. pt. 83 require NIOSH to evaluate qualified petitions requesting that the 

Department of Health and Human Services (HHS) add a class of employees to the SEC. The 

evaluation is intended to provide a fair, science-based determination of whether it is feasible to 

estimate with sufficient accuracy the radiation doses of the class of employees through NIOSH dose 

reconstructions.

2

 

42 C.F.R. § 83.13(c)(1) states: Radiation doses can be estimated with sufficient accuracy if NIOSH 

has established that it has access to sufficient information to estimate the maximum radiation dose, 

for every type of cancer for which radiation doses are reconstructed, that could have been incurred in 

plausible circumstances by any member of the class, or if NIOSH has established that it has access to 

sufficient information to estimate the radiation doses of members of the class more precisely than an 

estimate of the maximum radiation dose.

Under 42 C.F.R. § 83.13(c)(3), if it is not feasible to estimate with sufficient accuracy radiation doses 

for members of the class, then NIOSH must determine that there is a reasonable likelihood that such 

radiation doses may have endangered the health of members of the class. The regulation requires 

NIOSH to assume that any duration of unprotected exposure may have endangered the health of 

 1 DCAS was formerly known as the Office of Compensation Analysis and Support (OCAS).

2 NIOSH dose reconstructions under EEOICPA are performed using the methods promulgated under 42 C.F.R. pt. 82 and 

the detailed implementation guidelines available at http://www.cdc.gov/niosh/ocas.
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members of a class when it has been established that the class may have been exposed to radiation 

during a discrete incident likely to have involved levels of exposure similarly high to those occurring 

during nuclear criticality incidents. If the occurrence of such an exceptionally high-level exposure has 

not been established, then NIOSH is required to specify that health was endangered for those workers 

who were employed for at least 250 aggregated work days within the parameters established for the 

class or in combination with work days within the parameters established for one or more other SEC 

classes.

NIOSH is required to document its evaluation in a report, and to do so, relies upon both its own dose 

reconstruction expertise as well as technical support from its contractor, Oak Ridge Associated 

Universities (ORAU). Once completed, NIOSH provides the report to both the petitioner(s) and the 

Advisory Board on Radiation and Worker Health (Board). The Board will consider the NIOSH 

evaluation report, together with the petition, petitioner(s) comments, and other information the Board 

considers appropriate, in order to make recommendations to the Secretary of HHS on whether or not 

to add one or more classes of employees to the SEC. Once NIOSH has received and considered the 

advice of the Board, the Director of NIOSH will propose a decision on behalf of HHS. The Secretary 

of HHS will make the final decision, taking into account the NIOSH evaluation, the advice of the 

Board, and the proposed decision issued by NIOSH. As part of this decision process, petitioners may 

seek a review of certain types of final decisions issued by the Secretary of HHS.

3

3.0 SEC-00216, Dow Chemical Company Class Definitions

The following subsections address the evolution of the class definition for SEC-00216, Dow Chemical 

Company. When a petition is submitted, the requested class definition is reviewed as submitted. 

Based on its review of the available site information and data, NIOSH will make a determination 

whether to qualify for full evaluation all, some, or no part of the petitioner-requested class. If some 

portion of the petitioner-requested class is qualified, NIOSH will specify that class along with a 

justification for any modification of the petitioner’s class. After a full evaluation of the qualified 

class, NIOSH will determine whether to propose a class for addition to the SEC and will specify that 

proposed class definition.

3.1 Petitioner-Requested Class Definition and Basis

Petition SEC-00216 was received on June 12, 2014, and qualified on August 5, 2014. The petitioner 

requested that NIOSH consider the following class: All employees in all areas who worked for Dow 

Chemical Co. in Pittsburg, CA (aka Walnut Creek, CA), from 1947-1957.

The petitioner provided information and affidavit statements in support of the petitioner’s belief that 

accurate dose reconstruction over time is impossible for the Dow Chemical Company workers in 

question. NIOSH deemed the following Form B and affidavit statements sufficient to qualify SEC00216 for evaluation:

• Records and information are inadequate to estimate radiation doses acquired by members 

of the proposed class of employees with sufficient accuracy.

 3 See 42 C.F.R. pt. 83 for a full description of the procedures summarized here. Additional internal procedures are 

available at http://www.cdc.gov/niosh/ocas.
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• The DOL description states: The DOW operation involved process studies and 

experimentation investigations on different uranium ores and thorium-bearing ores, 

including pilot-scale solvent extraction from phosphoric acid.

Based on its Dow Chemical Company research and data capture efforts, NIOSH determined that it has 

access to process descriptions for many of the research operations that went on at Dow Chemical 

Company during the time period under evaluation. However, NIOSH also determined that no 

personnel, area, or air monitoring records exist for all time periods or for all radionuclides. NIOSH 

concluded that there is sufficient documentation to support, for at least part of the requested time 

period, the petition basis that radiation exposures and radiation doses were not adequately monitored 

at Dow Chemical Company, either through personal monitoring or area monitoring. The information 

and statements provided by the petitioner qualified the petition for further consideration by NIOSH, 

the Board, and HHS. The details of the petition basis are addressed in Section 7.4 of this report.

3.2 Class Evaluated by NIOSH

Based on its preliminary research, NIOSH accepted the petitioner-requested class because of the lack 

of any monitoring records for the Dow Chemical Company facility in Pittsburg, California, for the 

period of AEC operations. Therefore, NIOSH defined the following class for further evaluation: All 

employees who worked in any area of the Dow Chemical Company facility in Pittsburg, California, 

from January 1, 1947 through December 31, 1957.

3.3 NIOSH-Proposed Class to be added to the SEC

Based on its research of the class under evaluation, NIOSH has defined a single class of employees for 

which NIOSH cannot estimate radiation doses with sufficient accuracy. The NIOSH-proposed class 

to be added to the SEC includes all Atomic Weapons Employer employees who worked for Dow 

Chemical Company in Pittsburg, California, from October 1, 1947 through June 30, 1957, for a 

number of work days aggregating at least 250 work days, occurring either solely under this 

employment or in combination with work days within the parameters established for one or more 

other classes of employees included in the Special Exposure Cohort.

The NIOSH-proposed class was modified from the NIOSH-evaluated class because during its 

evaluation NIOSH found documentation regarding the start and end dates for the AEC work; the

initiation of the contract with AEC began on October 1, 1947, while the contract was completed June 

30, 1957 (Contract AT-30-1-GEN-236; Johnson, 1957). The periods from January 1, 1947 through

September 30, 1947, and from July 1, 1957 through December 31, 1957, have been excluded from the 

NIOSH-proposed class because covered work was not performed during these times. The scope of 

workers included in the class was not modified from the petitioner-requested class description of “all 

workers”. Though a former worker indicated that it was not the custom for individuals to enter labs 

they were not working in, it seems there were no access controls to prevent it. With no administrative 

or engineered controls to prevent access to the source terms at Dow Chemical Company, and no 

monitoring program to detect possible exposures, NIOSH cannot differentiate the potentially-exposed 

worker population from workers with no potential for exposure, based on available documentation. 
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NIOSH also investigated the description of the site location provided as part of the petition. 

Information NIOSH gathered indicates that the Walnut Creek facility was not built until after the 

covered period of AEC operations. Because the Walnut Creek location was not in existence during 

the AEC operations, any operations at that location are excluded as they are not EEOICPA-covered 

activities. Therefore, the NIOSH-proposed class indicates only Pittsburg, California, and no further 

investigations into work at the Walnut Creek facility are reported herein.

4.0 Data Sources Reviewed by NIOSH to Evaluate the Class

As is standard practice, NIOSH completed an extensive database and Internet search for information 

regarding Dow Chemical Company. The database search included the DOE Legacy Management 

Considered Sites database, the DOE Office of Scientific and Technical Information (OSTI) database, 

the Energy Citations database, and the Hanford Declassified Document Retrieval System. In addition 

to general Internet searches, the NIOSH Internet search included OSTI OpenNet Advanced searches, 

OSTI Information Bridge Fielded searches, Nuclear Regulatory Commission (NRC) Agency-wide 

Documents Access and Management (ADAMS) web searches, the DOE Office of Human Radiation 

Experiments website, and the DOE-National Nuclear Security Administration-Nevada Site Officesearch. Attachment One contains a summary of Dow Chemical Company documents. The summary 

specifically identifies data capture details and general descriptions of the documents retrieved.

In addition to the database and Internet searches listed above, NIOSH identified and reviewed 

numerous data sources to determine information relevant to determining the feasibility of dose 

reconstruction for the class of employees under evaluation. This included determining the availability 

of information on personal monitoring, area monitoring, industrial processes, and radiation source

materials. The following subsections summarize the data sources identified and reviewed by NIOSH.

4.1 Site Profile Technical Basis Documents (TBDs)

A Site Profile provides specific information concerning the documentation of historical practices at 

the specified site. Dose reconstructors can use the Site Profile to evaluate internal and external 

dosimetry data for monitored and unmonitored workers, and to supplement, or substitute for, 

individual monitoring data. A Site Profile consists of an Introduction and five Technical Basis 

Documents (TBDs) that provide process history information, information on personal and area

monitoring, radiation source descriptions, and references to primary documents relevant to the 

radiological operations at the site. While a Site Profile document was not developed for the Dow 

Chemical Company site, NIOSH examined the following TBD for insights into Dow Chemical 

Company operations or related topics/operations at other sites:

• Technical Basis Document for Atomic Energy Operations at Blockson Chemical Company, Joliet, 

Illinois, DCAS-TKBS-0002; Rev. 03; November 21, 2007; SRDB Ref ID: 91205

4.2 ORAU Technical Information Bulletins (OTIBs)

An ORAU Technical Information Bulletin (OTIB) is a general working document that provides 

guidance for preparing dose reconstructions at particular sites or categories of sites. NIOSH reviewed 

the following OTIBs as part of its evaluation:
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• OTIB: Dose Reconstruction from Occupational Medical X-Ray Procedures, ORAUT-OTIB-0006, 

Rev. 4; June 20, 2011; SRDB Ref ID: 98147

• OTIB: Estimation of Neutron Dose Rates from Alpha-Neutron Reactions in Uranium and Thorium 

Compounds, ORAUT-OTIB-0024 , Rev.00; April 7, 2005; SRDB Ref ID: 19445

• OTIB: Guidance on Assigning Occupational X-Ray Dose Under EEOICPA for X-Rays 

Administered Off Site, ORAUT-OTIB-0079, Rev. 00; January 3, 2011; SRDB Ref ID: 89563

4.3 Facility Employees and Experts

To obtain additional information, NIOSH interviewed three former Dow Chemical Company

employees. NIOSH tried to locate additional former employees, but all that were identified to NIOSH 

as associated with this work that occurred over 50 years ago are deceased. NIOSH’s objective was to 

gather information on specific radioactive material operations at the Dow Chemical Company facility 

in Pittsburg, California, to clearly determine the location of the radiation work conducted and to 

identify any radiological monitoring performed during operations. Interviews were performed by 

telephone with a minimum of one NIOSH and two ORAU Team personnel in attendance. NIOSH 

also contacted a former worker associated with the Formerly Utilized Sites Remedial Action Program 

(FUSRAP) elimination survey for the site. That individual declined to be interviewed. 

• Personal Communication, 2014a, Personal Communication with Former Dow Chemical Company

Employee ; Telephone Interview by ORAU Team and NIOSH; August 29, 2014; SRDB Ref ID: 

135915

• Personal Communication, 2014b, Personal Communication with Former Dow Chemical Company

Employee; Telephone Interview by ORAU Team and NIOSH; September 2, 2014; SRDB Ref ID: 

135930

• Personal Communication, 2014c, Personal Communication with Former Dow Chemical Company

Employee; Telephone Interview by ORAU Team and NIOSH; September 11, 2014; SRDB Ref 

ID: 136594

4.4 Previous Dose Reconstructions

NIOSH reviewed its NIOSH DCAS Claims Tracking System (referred to as NOCTS) to locate

EEOICPA-related dose reconstructions that might provide information relevant to the petition 

evaluation. Table 4-1 summarizes the results of this review. (NOCTS data available as of January 7, 

2015)
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Table 4-1: No. of Dow Chemical Company Claims Submitted Under the Dose Reconstruction Rule

Description Totals

Total number of claims submitted for dose reconstruction 1

Total number of claims submitted for energy employees who worked during the period under 

evaluation (January 1, 1947 through December 31, 1957) 1

Number of dose reconstructions completed for energy employees who worked during the period

under evaluation (i.e., the number of such claims completed by NIOSH and submitted to the 

Department of Labor for final approval). 1

Number of claims for which internal dosimetry records were obtained for the identified years in the 

evaluated class definition 0

Number of claims for which external dosimetry records were obtained for the identified years in the 

evaluated class definition 0

NIOSH reviewed the single claim to determine whether internal and/or external personal monitoring 

records could be obtained for the employee. No personal monitoring records were located for the 

claim and a maximizing approach was applied to over-estimate the possible exposure this individual 

could have received. No indications of any discrete incidents were located.

4.5 NIOSH Site Research Database

NIOSH also examined its Site Research Database (SRDB) to locate documents supporting the 

assessment of the evaluated class. One hundred sixty-six documents in this database were identified 

as pertaining to Dow Chemical Company. These documents were evaluated for their relevance to this 

petition. The documents include historical background on the development of chemical processes 

investigated and assessed by Dow Chemical Company for the recovery of uranium as a byproduct of 

the commercial phosphate processing industry. Information on process materials and process 

descriptions were included.

4.6 Documentation and/or Affidavits Provided by Petitioners

In qualifying and evaluating the petition, NIOSH reviewed the following documents submitted by the 

petitioners:

• Form B, June 11, 2014 (DSA Ref ID: 120003); 

• Newspaper article, Exhibit Building was Center of Most Attention at Fair, The Antioch Ledger;

August 13, 1951 (DSA Ref ID: 120083, PDF p. 4);

• Handout, Information about the Displays: Gamma the Glutton A Dipper Bird, a handout 

for use in explaining specific exhibits (DSA Ref ID: 120083, PDF pp. 6-9); and

• Affidavit from Survivor, indicating that records and information are inadequate to estimate the 

radiation doses acquired by members of the proposed class with sufficient accuracy; June 30, 2014 

(DSA Ref ID: 120083, PDF pp. 2-3).
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5.0 Radiological Operations Relevant to the Class Evaluated by 

NIOSH

The following subsections summarize both radiological operations at the Dow Chemical Company

from January 1, 1947 through December 31, 1957, and the information available to NIOSH to 

characterize particular processes and radioactive source materials. From available sources NIOSH has 

gathered descriptive information regarding the uranium source of concern, and information describing 

processes through which radiation exposures may have occurred and the physical environment in 

which they may have occurred. The information included within this evaluation report is intended 

only to be a summary of the available information. 

5.1 Dow Chemical Company Plant and Process Descriptions

The AEC, in an effort to ensure domestic production of uranium, pursued options to adapt the 

processes for recovering uranium from pitchblende and carnotite ores to the problem of recovering 

uranium from phosphate ores. The goal was to develop large, low-grade deposits of shales, 

phosphates, and lignites into economical sources of uranium. Emphasis was placed on phosphate rock 

(Greek, 1957, PDF p. 3), which contains about 0.01% U3O8 (Bailes, 1951, PDF p. 5). The uranium is 

evenly distributed through the phosphate rock and consequently cannot be concentrated by mechanical 

methods. 

Phosphate ores, already in use at the time to manufacture phosphate fertilizers and phosphate 

chemicals, offered an economic advantage because the mining itself was not a cost to the government. 

The phosphate ore deposits were being mined for these commercial products and the uranium would 

be extracted as a byproduct operation. Uranium Recovery from Wet Process Phosphoric Acid (Greek,

1957, PDF p. 3) estimates a ton of phosphate rock generally contains 0.1 to 0.4 pounds of uranium. 

Occasionally a deposit was found with uranium content up to 1 pound per ton of phosphate rock. 

On February 17, 1948, the AEC initiated Contract No. AT-30-1-GEN-236 with Dow Chemical 

Company to “conduct certain studies and experimental investigations on uranium and thorium-bearing 

ores designated by the Commission...” (Contract AT-30-1-GEN-236, PDF p.4). The contract was 

effective October 1, 1947, and extended annually to June 30, 1957, by Supplement 12 (DOE, 

unknown, PDF p. 13). The contract called for process studies and pilot-scale solvent extraction of 

uranium from phosphoric acid with Supplement 2 adding studies on liquid waste disposal. The 

studies during the nine-and-a-half years of work pertained to uranium recovery from a variety of raw 

materials and improving concentrates to yield specification-grade uranium compounds. Precipitation, 

ion exchange, and solvent extraction were investigated as potential methods. Investigations were 

carried out by Dow Chemical Company into uranium recovery from phosphates, superphosphates,

low-content leached zone phosphates, sulfuric acid leach solutions (from the Colorado Plateau mills), 

carbonate leach liquors, Mallinckrodt uranium refinery nitrate raffinates and carbonate scrub 

solutions, phosphate ores by direct-solvent uranium extraction (without prior aqueous leaching), and 

from other miscellaneous materials. Numerous original contributions to uranium-ore metallurgy came 

from this work. Most of the work for the last year of the contract was concerned with methods for the 

production of specification-grade UF4 products at the mill site. Reduced uranium could be extracted. 

UF4 products of high purity were obtained by precipitation that approached the chemical specifications 
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(Bailes, 1957, PDF p. 14). The studies suggested that integration of raw material and feed material 

production in the mills producing crude concentrate was feasible, at a considerable cost savings.

Dow Chemical Company was located in Pittsburg, California, on a multi-acre site. Although NIOSH 

does not have documentation providing the dimensions of the physical site during the period under 

evaluation, the current Dow Chemical Company site in Pittsburg, California, encompasses 513 acres, 

472 of which are wetlands preserve, leaving 41 acres available for operational use. The uraniumrecovery work was located in the Research Laboratory building, along with other research groups. 

The building was a two-story building with approximately 7-8 offices for supervisors and clerical 

personnel as well as meeting rooms at one end. It also contained a storeroom and a library. The top 

floor had 7-8 laboratories, including the analytical laboratory, which supported all the projects in the 

Research Laboratory building, including sample analysis for the AEC work. The AEC uranium work 

was carried out on the top floor. The first floor was principally devoted to Dow’s fiber project, which 

was a Dow commercial project that is not associated with work for the AEC and was not associated 

with radiological materials (Personal Communication, 2014 a,b,c).

The amount of space within the building allotted to the AEC work varied from a minimum of a single 

600-square-foot laboratory up to a maximum of 7 labs (2.5 laboratory rooms for research, 2 for pilotplant work, and 2.5 for analytical work) spread over 4,200 square feet (Bailes, 1957). For the period 

evaluated by NIOSH, the Dow Chemical Company workforce consisted of approximately 100 

workers. A total of 22 research chemists and chemical engineers were engaged in the laboratory and 

pilot plant investigations, six of whom worked on the project for the greater part of the contract. Eight 

technicians assisted in the laboratory work and four operators worked in the pilot plant operations. 

The analytical staff members were assisted by 53 analysts during the Atomic Weapons Employer

(AWE) operational period. Intermittently, additional chemical engineers were needed for cost 

estimation and plant design; their assistance was arranged from the Dow Research Engineering group 

as needed. Five such engineers worked on the AEC project for some period. The AEC engineer 

group had access to the regular library, stockroom, purchasing, glass-blowing, and machine shop 

facilities of the Dow Research Department. Including librarians, warehouse or stockroom employees, 

purchasing, etc., NIOSH estimates 100 workers were directly involved in the work. 

Phosphoric acid was chosen as the starting material for the recovery investigations at Dow Chemical 

Company. Since the uranium in phosphate rock is dissolved in the acid solution when the rock is 

converted to phosphoric acid, the acid solution appeared to be the most promising starting material for 

recovery (Bailes, 1957). Commercial phosphoric acids were obtained for testing from a large number 

of plants. These acids came from Florida phosphate mining or processing operations and phosphate 

mining operations in the western United States (i.e., Montana-Anaconda Copper Mining Company 

Plant in Anaconda, Montana) (Bailes, 1957, PDF p. 9). The Topical Report DOW-162, which 

summarizes the research work performed for the AEC, states that 248,463 uranium analyses and 

78,081 other analyses were made at the Dow Research Laboratory (Bailes, 1957, PDF p. 16). The

Dow Spectrographic Laboratory at Midland, Michigan, made 44 analyses of purified products for 

trace impurities (Bailes, 1957, PDF p. 16). Assuming, based on interview statements, that the samples 

to be analyzed were on the order of 200-300 ml each, this would suggest a quantity of approximately 

65-100 kilolitres or 17,000-26,500 gallons of solution over the nine-and-a-half years. This estimate is 

quite imprecise and cannot be used to base any definite conclusions on. It is simply provided to

roughly demonstrate the scale of the facility’s work.
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Precipitation Method

The precipitation method was the first successful method in recovering uranium at Dow. The first 

process was known as the fluoride process and consisted of passing the acid through a column packed 

with iron to reduce all the uranium to the +4 state. This step consumed about 1 gram of iron per liter 

of acid. Then CaO and hydrofluoric acid (HF) were added, which precipitated the uranium in a 0.3% 

U3O8 cake. The uranium was then leached from the precipitate with Na2CO3 or dilute acids. The 

uranium products were processed from the leach by standard chemical methods (Bailes, 1951, PDF 

pp. 7-8). According to a Progress Report for January 1949 (Bailes, Feb1949), fluoride precipitations

were carried out on a 2- or 5-liter scale, with the next goal being to progress to batch processing 5-10 

gallons of acid at a time. Several precipitations were made using the raw phosphate rock as a source 

of calcium. A Progress Report for February 1949 (Bailes, Mar1949, p. 3) describes the construction 

and operation of a test plant for uranium reduction and precipitation from 50-100 pound batches of 

35% phosphoric acid (H3PO4) in 4 hours. The report includes a picture of the test plant, which would 

easily have been housed in one of the Dow labs. The report also describes work with precipitate cakes 

and samples (Bailes, Mar1949, p. 15). The Progress Report for February 1949 mentions quantities on 

the order of 50 grams of precipitate, over 50 grams of residue, and 400-500 ml of leach. These were 

handled and/or analyzed for content. A table of results is provided (Bailes, Mar1949, p. 16). 

Hydrochloric acid leaching experiments in 600 ml beakers are also described (Bailes, Mar1949, p. 

16). The precipitate was ground to 30-mesh size, presumably onsite.

Another process proved to be more efficient. It used Sb2O3 as a precipitant, which left the uranium in 

an ammonium-phosphate solution. When the solution was heated the uranium precipitated out and 

gave a 13% U3O8 cake. 

The HF used to precipitate the calcium in the first process was too expensive to be an economical 

choice so that path of investigation ended. The antimony process, which used Sb2O3 as a precipitant, 

was abandoned because estimates indicated ion exchange would be less expensive.

Some investigations looked into uranium recovery during the manufacture of ammonium phosphates 

by neutralization of phosphoric acid. These preliminary laboratory investigations at Dow Chemical 

Company led to the development of a process involving the oxidation of the uranium in the acid with 

chlorine, neutralization, filtration, and then precipitation of uranium as uranous phosphate.

The Progress Report for July 1949 (Bailes, Jul1949) specifically reported on tests into the effect of 

time and temperature on related parts of the processes. Precipitation process samples would have 

undergone physical handling to include heating, stirring, agitation, filtration, pouring, pipetting, 

drying, crushing, and grinding during uranium recovery or analysis.

Ion Exchange

The original ion-exchange process was developed by Dow, with work continuing over the AEC 

operational period to refine the uranium recovery process so that it was economical and efficient. 

Concurrently with the development of the precipitation processes, Dow began to investigate the use of 

ion-exchange resins. It was found that uranium as an anion could be adsorbed from phosphoric acids 

by anion-exchange resins. The preliminary work on the phosphoric acid-ion exchange process was 

done with acid from Montana. This acid contained vanadium and uranium. The process included 

adsorption of both metals and separation by selective elution. The vanadium was eluted first by 
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reduction with sulfur dioxide, and then the uranium was eluted with dilute sodium-chloride solution. 

Investigations into the effect of different exchange resins, the oxidation state with respect to resin 

efficiency, impurities in the acid, resin mesh size, column diameter, flow rate, and temperature were 

conducted (Bailes, Aug1949). A Progress Report for November 1949 (Bailes, Nov1949) indicates 

that “to avoid excessive use of manpower and to obtain resin-life data in the shortest possible time, an 

automatic ion exchange column operator was designed and constructed which operates an ion 

exchange column through a complex cycle on a 24-hour basis with no attention." Page 59 of the 

November 1949 Progress Report describes operation of the automatic controller and an incident where 

a sintered glass disk holding the resin bed broke through after 80 cycles and the resin was lost. Each 

cycle used 500 ml of commercial phosphoric acid, so some loss of uranium was possible (Bailes, 

Nov1949).

A laboratory-scale pilot plant was operated initially at the Pittsburg laboratory, and the process was 

tested for several months (Bailes, 1957, PDF p. 18). A Dow report, Recovery of Uranium and 

Vanadium from Phosphoric Acid Solution by Ion Exchange, dated March 22, 1951 (Bailes, 1951, PDF 

p. 15), describes the laboratory-scale pilot plant as consisting of a 4-column unit of 2-inch diameter 

columns containing about 1.5 liters of wet-settled resin each. The columns were constructed of Pyrex 

glass pipe with jackets for heating or cooling. Solutions were fed into the columns with pumps or 

pressurized vessels and controlled by means of a series of stopcocks. They could be operated 

individually or in series. 

The pilot investigations were successful, a larger pilot plant was designed and a cost estimate to build 

it was developed in April 1950. The March 1951 report indicates that a pilot plant with a capacity of 

1,000 gallons per day of 30% H3PO4 for both vanadium and uranium recovery was designed and built, 

but the report does not specify the location (Bailes, 1951, PDF p. 43). NIOSH has found reference to 

a large-scale pilot plant that was built at East Tampa, Florida, by the U.S. Phosphoric Products 

Corporation, with two Dow engineers deployed there for several months to assist in the engineering 

and operation of this plant (Bailes, 1957, PDF p. 9; Wilkinson, 1976, PDF p. 11). These pilot plant 

investigations identified a number of problems which could not have been determined in the previous 

laboratory work. For the low-uranium-content Florida phosphoric acid, the process was too expensive 

and was abandoned and deemed economically impractical. This was because none of the available 

resins had the specific affinity for uranium; the resin load would be made up of calcium, iron, 

aluminum, and vanadium ions with very little uranium. These findings, coupled with the increased 

discoveries of uranium in the Rock Mountain basin area, made this process economically unattractive. 

In view of these findings, Dow developed a solvent-extraction process based on organic, phosphate 

esters.

Solvent Extraction

The ion-exchange process was abandoned for the solvent-extraction method. Alkyl pyrophosphoric 

acid solvent was found to extract uranium from phosphoric acid. Later, additional work was carried 

out to show how alkyl orthophosphates could be used to extract uranium from most any leach liquor. 

Alkyl pyrophosphate extracts the uranium from the phosphoric acid forming a complex compound 

with bonding similar to a chelate or a true chemical bond as in ion exchange. After separation, the 

organic complex in a diluent has removed as much of other ions as possible by precipitation with 

sulfuric acid. The uranium is then recovered from the complex by reacting it with hydrofluoric acid. 

Recovered uranium, as uranium tetrafluoride (UF4), in a complex salt was dried and shipped to AEC 
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installations for further processing. Alkyl pyrophosphates with chain lengths from 4 to 17 carbon 

atoms were investigated to find the extracting power increases with the chain length up to 17 carbon 

atoms. The physical properties of the alkyl pyrophosphates were also investigated (Greek, 1957). An 

application (Patent Number 2859092A) was filed on February 5, 1953, for the solvent-extraction 

method for the recovery of metals from phosphoric acid. Three pilot-plant operations were 

implemented to confirm the solvent-extraction method; one at International Minerals and Chemical 

Company under a contract dated April 26, 1951, which was shut down in 1959; one at Armour 

Fertilizer Works on the W.R. Grace Co. property operating from late November to late December 

1954; and one at U.S. Phosphoric Products Company in East Tampa, Florida (Unknown, 2001, PDF p. 

28). Some pilot plant research into solvent extraction was also being researched at the U.S. Bureau of 

Mines plant in Salt Lake City. Reports mention a problem of large losses of solvent through 

entrainment in the heavy slurry systems at the Salt Lake City pilot plant (Bailes, Nov1955). While 

larger-scale work was ongoing at pilot plants, the research to resolve this and other problems 

encountered was performed at Dow Chemical Company. At Dow, slurry and organic feed rates were 

100 ml/min at the lab mixer.

Additional pilot plants were later built to test the solvent-extraction process. These included one built 

by Mathieson Chemical Company, Pasadena, Texas; one by U.S. Phosphoric Products Company, 

Tampa, Florida; and one by International Mineral and Chemical Company, near Bartow, Florida. 

These plants were not staffed by Dow employees, although one employee did make several visits to 

the Mathieson pilot plant in Texas and assisted in its operation (Bailes, 1957, PDF p. 10). 

Based on this pilot-plant work, four solvent-extraction recovery plants were built, one each at Texas 

City Chemicals, Inc. in Texas City, Texas; Virginia-Carolina Chemical Corp. in Nichols, Florida; 

International Minerals and Chemicals in Bonnie, Florida; and U.S. Phosphoric Products Company in 

Tampa, Florida. 

Neither the Texas City Chemicals nor the Virginia-Carolina Chemical plants ever achieved production 

capacity. International Minerals and Chemical Company and U.S. Phosphoric Products began 

production in 1955. U.S. Phosphoric Products signed a contract (AT(49-6)-912) with the AEC in 

December 1954, to construct and operate a byproduct uranium-recovery plant with an estimated 

production of 60 tons of U3O8 per year. Operations at this plant were discontinued in 1960 when U.S. 

Phosphoric Products and the AEC came to a mutual agreement to terminate the contract (Unknown, 

post-Nov1980, PDF p. 65).

Uranium Extraction from Phosphate Rock

Although recovery research primarily used commercial phosphoric acids from the various industrial 

plants as the initial sample material (Bailes, 1957, PDF p. 7), a laboratory study was also performed 

regarding the manufacture of phosphoric acid from phosphate rock. The purpose of the study was to 

determine the best conditions for uranium dissolution in the acid, from which the uranium could later 

be recovered. 

Direct Solvent Leaching of Uranium Ores with Alkyl Phosphates (Magner, 1957) describes direct ore

leaching with organic solvents in detail. The report describes a result based on 100 pounds of sulfuric 

acid per ton of ore (Magner, 1957, p. 8). This, superficially, indicates they worked with a ton of ore to 

achieve the results, but no detail is provided on whether this was done at Dow or at one of the other 
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pilot plants. It also doesn't provide clear evidence that the work involved this quantity, as the results 

may have been scaled to provide comparable units. The description of work (Magner, 1957, p. 9) also

indicates that data on the effects of variables were based on work with small batch samples and the 

ratios of volume-to-weight of ore were known and varied to determine the quantity of extractant 

required. The amount of acid was equivalent to 48 pounds per ton of ore in 2 series of tests. A 

sample of the ore as received was screened and separated into fractions according to mesh size 

(Magner, 1957, p. 27). Dow found the uranium recovery did not increase enough to justify the cost of 

grinding operations. Investigations were conducted into percolation leaching (Magner, 1957, p. 35), 

the application of acidified solvent to the ore, and removal after short contact time. This involved a

continuous counter-current system with ore carried on a moving belt while dripping solvent onto the 

surface, percolating through the ore to leach materials directly. Dow also investigated columnar 

percolation leaching with the acid percolated through ore in a column configuration to leach products 

from the ore.

African Ore

Topical Report Dow-162, Table I (Bailes, 1957, PDF pp. 19-20) contains a list of research subjects 

and provides the status and related topical and progress reports containing those subjects. One subject 

in the table, “U from Miscellaneous African MgX ore” has raised concern that Dow might have 

performed work with African ores. The table indicates that progress reports 35-38 and 40 contain 

reference to this topic, and the code letter for the subject is W. Table II of Topical Report Dow-162

lists these same reports (35-38 and 40) with dates ranging from September 1950 through December 

1950. Topical Report Dow-162 lists South African project reports and states that the reports 

summarize work in South Africa on a project to introduce uranium recovery by ion exchange in gold 

mills there (Bailes, 1957, PDF 28). This work was presumably under the Dow contract, and at least 

one Dow employee may have received exposure at the South African mills. However, this project 

would not likely have introduced African ores to the Dow Chemical Company site. 

Waste Phosphatic Materials

Dow investigated processes to recover uranium from low-grade phosphate materials, which are 

considered waste materials from a commercial perspective (Stoltz, 1958). These materials, also called 

leach-zone materials in the phosphate industry, contain from three to five times more uranium than the 

phosphate ores recovered as products of the Florida mining operations (Stoltz, 1958, PDF p. 3). The 

leach zone overlies the calcium phosphate rock matrix and because it contains only 10-12% P2O5, it is 

generally discarded as waste material by the phosphate mining industry. This leach-zone ore was 

investigated by Dow Chemical Company for possible methods for recovering the uranium it 

contained, none of which proved to be economically self-sufficient. Dow Chemical Company’s 

laboratory work indicated the possibility of producing alumina, tri-sodium phosphate, ammonium 

phosphates, ammonium sulfate, and other products from so-called leached-zone ores. International 

Minerals and Chemical Company conducted extensive pilot plant testing on leached zone phosphates 

and prepared engineering estimates on plants capable of producing from 100 to 500 tons of uranium 

per year. These estimates showed none of these processes could economically produce uranium at the 

time of the investigations.
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5.2 Radiological Exposure Sources from Dow Chemical Company Operations

Available reports indicate that research at Dow Chemical Company involved uranium-bearing 

materials, and what is described in the FUSRAP documentation of the contract language as “thorium 

bearing ores.” However, the documentation does not provide sufficient information on specific

quantities, or forms of the source materials used at any given time during the period under evaluation. 

Given this lack of information, NIOSH is unable to make supported assumptions about source terms, 

concentrations, or radiological equilibrium conditions at the Dow Chemical Company facility for the 

period from October 1, 1947 through June 30, 1957.

Considerable detail regarding the chemistry processes under investigation is found in the Dow 

Progress Reports and Research Reports. These reports provide descriptions of the processes and 

chemical interactions investigated, but do not provide the level of quantitative information that 

NIOSH looks for during evaluation of facility exposure potential. The reports describe samples and 

test runs as larger- and smaller-scale, but without providing any quantitative information to define 

what is considered large or small. The scale of the processes and the work is completely absent from 

these reports. This information has been reviewed and considered in this evaluation by NIOSH, but 

has not been provided in depth in this report. The following subsections provide a summary of the

limited internal and external exposure source documentation available to NIOSH for the Dow 

Chemical Company class under evaluation.

5.2.1 Internal Radiological Exposure Sources from Dow Chemical Company Operations

Research at Dow Chemical Company involved natural uranium-bearing phosphatic solutions received 

from commercial sources. These materials were sources of potential radiological exposure at the site. 

5.2.1.1 Uranium

The primary source of internal radiological exposure was inhalation and/or ingestion of natural 

uranium, which generally is defined to include approximately 0.7% U-235, 99.3% U-238, and a very 

small residual amount of U-234, by weight. In terms of radioactivity, natural uranium contains 

approximately equal percentages of U-238 (48.6%) and U-234 (49.2%). These radionuclides emit 

alpha particles with primary emission energies of 4.20 MeV and 4.15 MeV (U-238), and 4.77 MeV 

and 4.72 MeV (U-234) (Rad Handbook, 1970). The radioactivity contribution from U-235 is much 

smaller (approximately 2.2%) relative to U-238 or U-234. U-235 emits alpha particles with energies 

of 4.40 MeV and 4.37 MeV. Other alpha-emitting radionuclides, including radon and progeny, occur 

naturally as part of the U-238 decay process.

5.2.1.2 Thorium

There have been indications in the contract and FUSRAP reports of work that used thorium-bearing 

ores at Dow Chemical Company. NIOSH has not found clear documentation of specific research

work focusing on thorium.
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5.2.2 External Radiological Exposure Sources from Dow Chemical Company Operations

Based on information and documentation available to NIOSH, the potential for external radiation 

doses from uranium and uranium-decay products existed at the Dow Chemical Company site. The 

uranium was naturally-occurring, derived from phosphate rock, with natural isotopic abundance. The 

following subsections provide an overview of the external exposure sources. 

Natural uranium emits both beta particles (electrons) and photons (X-ray and gamma photons), as 

shown in Table 5-1. The two primary components of natural uranium are U-238 and U-235.

5.2.2.1 Photon

External exposures to photon radiation would have resulted from the immediate daughter 

radionuclides in the uranium decay chain. The uranium progeny that result in the most significant 

photon exposures include Th-234 and Pa-234m (Rad Handbook, 1970). Note that these isotopes have 

relatively short half-lives and can be assumed to be in equilibrium with the parent U-238. Because of 

their short half-lives, the exposure potential from these isotopes would travel with the parent and will

not be considered separately. Photon emissions from uranium during the period under evaluation 

would include emissions from uranium progeny (mainly Ra-226 and radium progeny).

The majority of the photons from natural uranium isotopes are in the 30-250 keV energy range 

(ORAUT-OTIB-0004).

5.2.2.2 Beta

Any beta radiation fields at Dow Chemical Company would have been the result of contributions from 

uranium progeny radionuclides following the uranium during the acid leaching at the mining facilities. 

For example, nearly the entire beta radiation field from U-238 comes from the daughter radionuclide 

Pa-234m, and to a lesser extent from Th-234. Operations at Dow Chemical Company were not 

known to concentrate progeny elements specifically, but there is potential for such concentration, 

especially in the resin ion-exchange process and the precipitation-recovery process investigations. 

Table 5-1 shows the beta emitters and their energies for the uranium and thorium natural decay series 

that might have been present in the phosphatic acid at Dow Chemical Company. There are a 

significant number of high-energy beta radiations that represent a shallow dose exposure concern for 

Dow Chemical Company workers in close proximity to the solutions that were being researched. 

Workers handling the bench-level experiments on the uranium- and thorium-bearing solutions would 

have received shallow dose exposures, primarily to the hands and forearms, and to a lesser extent, 

exposures to the neck and face.

Chemical processing (e.g., phosphoric acid production) may alter the relative concentrations of 

uranium, thorium, radium, or other radionuclides from those found in the phosphatic-rock raw 

material. The various radioisotopes will fractionate according to chemical properties (Burnett, 1995). 

The distribution of specific uranium and thorium decay chain radionuclides within phosphate source 

material and within the various products and waste streams produced by the phosphate ore processing 

industry has been the subject of various studies. In general:
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• Radiological equilibrium in the uranium chain appears to be maintained in rock that has not been 

chemically processed (Roessler, 1979; Burnett, 1995); thus the phosphatic rock raw material is 

assumed to have been in equilibrium at the start of processing.

• Ra-226 and Po-210 are retained in the phosphogypsum (i.e., do not enter the phosphoric acid 

stream to any significant degree) (Guimond, 1975, PDF p. 15; Burnett, 1995, PDF pp. 1-16).

• Uranium and thorium tend to favor the phosphoric acid phase (Guimond, 1975; Burnett, 1995).

Table 5-1: Beta and Gamma Emissions of Primary Interest

Table 5-1 spans three pages.

Radionuclide Beta Energy 

(MeV, max.)

Gamma Energy 

(MeV)

Uranium-238 None None

Thorium-234 0.10 (19%)

0.193 (79%)

0.063 (3.5%)

0.093 (4%)

Protactinium-234m 2.28 (99%) 0.766 (0.2%)

1.00 (0.6%)

Uranium-234 None 0.053 (0.1%)

Thorium-230 None

0.0667 (0.37%)

0.142 (0.07%) 

0.144 (0.045%)

Radium-226* None 0.186 (3.28%)

Radon-222 None 0.510 (0.078%)

Polonium-218 0.33 (0.02%) 0.837 (0.0011%)

Lead-214

0.67 (48%)

0.73 (42.5%)

1.03 (6.3 %)

0.2419 (7.5%)

0.295 (19.2%)

0.352 (37.1%)

Bismuth-214

1.42 (8.3%)

1.505 (17.6%)

1.54 (17.9%)

3.27 (17.7%)

0.609 (46.1%)

1.12 (15.0%)

1.765 (15.9%)

2.204 (5.0%)

Polonium-214 None 0.7997 (0.010%)

Lead-210 0.016 (80%)

0.063 (20%) 0.0465 (4%)

Bismuth-210 1.161 (~100%) None

Polonium-210* None 0.802 (0.0011%)

Uranium-235 None

0.144 (11%)

0.163 (5%)

0.186 (54%)

0.205 (5%)

Thorium-231

0.205 (15%)

0.287 (49%)

0.304 (35%)

0.026 (15%)

0.084 (6.5%)
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Table 5-1: Beta and Gamma Emissions of Primary Interest

Table 5-1 spans three pages.

Radionuclide Beta Energy 

(MeV, max.)

Gamma Energy 

(MeV)

Protactinium-231 None 0.027 (6%)

0.29 (6%)

Actinium-227 0.043 (99%) 0.070 (0.08%)

Thorium-227 None

0.050 (8%)

0.237 (15%)

0.31 (8%)

Francium-223 1.15 (100%)

0.050 (40%)

0.080 (13%)

0.234 (4%)

Radium-223 None

0.149 (10%)

0.270 (10%)

0.33 (6%)

Radon-219 None 0.272 (9%)

0.401 (5%)

Polonium-215 0.74 (~.00023%) None

Lead-211

0.29 (1.4%)

0.56 (9.4%)

1.39 (87.5%)

0.405 (3.4%)

0.427 (1.8%)

0.832 (3.4%)

Bismuth-211 0.60 (0.28%) 0.351 (14%)

Thallium-207 1.44 (99.8%) 0.897 (0.16%)

Thorium-232 None 0.059 (0.19%)

0.126 (0.04%)

Radium-228 0.0389 (100%) 0.0067 (6 x 10-5%)

Actinium-228

0.983 (7%)

1.014 (6.6%)

1.115 (3.4%)

1.17 (32%)

1.74 (12%)

2.08 (8%)

(+33 more βs)

0.338 (11.4%)

0.911 (27.7%)

0.969 (16.6%)

1.588 (3.5%)

Thorium-228 None

0.084 (1.19%)

0.132 (0.11%)

0.166 (0.08%)

0.216 (0.27%)

Radium-224 None 0.241 (3.7%)

Radon-220 None 0.55 (0.07%)

Lead-212 0.346 (81%)

0.586 (14%)

0.239 (47%)

0.300 (3.2%)

Bismuth-212 1.59 (8%)

2.246 (48.4%)

0.040 (1%)

0.727 (11.8%)

1.620 (2.75%)
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Table 5-1: Beta and Gamma Emissions of Primary Interest

Table 5-1 spans three pages.

Radionuclide Beta Energy 

(MeV, max.)

Gamma Energy 

(MeV)

Thallium-208

1.28 (25%)

1.52 (21%)

1.80 (50%)

0.511 (23%)

0.583 (86%)

0.860 (12%)

2.614 (100%)

Note:

*Included for completeness but shown to separate into the gypsum phase and not an external exposure source at Dow Chemical 

Company.

5.2.2.3 Neutron

Uranium compounds can be a source of neutrons from spontaneous fission occurring in the isotopes of 

uranium and from alpha-neutron reactions with low atomic number materials such as oxides and 

impurities. Low-atomic-number elements (such as fluorine) emit neutrons of approximately 2 MeV 

energy when struck by alpha particles (referred to as alpha-neutron [“α-n”] reactions). The intensity 

of the radiation field from these reactions increases as a function of the enrichment. Estimation of 

Neutron Dose Rates from Alpha-Neutron Reactions in Uranium and Thorium Compounds (ORAUTOTIB-0024) describes the expected neutron dose rates from various forms of uranium compounds. 

Because only uranium-bearing byproducts with a natural isotopic ratio were researched at Dow 

Chemical Company, the neutron radiation field was significantly lower than the gamma component; 

therefore, neutrons are not considered a significant exposure concern and are not addressed further in 

this evaluation.

6.0 Summary of Available Monitoring Data for the Class Evaluated 

by NIOSH

The following subsections provide an overview of the state of the available internal and external 

monitoring data for the Dow Chemical Company class under evaluation.

6.1 Available Dow Chemical Company Internal Monitoring Data

The primary data used for determining internal exposures are derived from personal monitoring data, 

such as urinalyses, fecal samples, and whole-body counting results. If these are unavailable, the air 

monitoring data from breathing zone and general area monitoring are used to estimate the potential 

internal exposure. If personal monitoring and breathing zone area monitoring are unavailable, internal 

exposures can sometimes be estimated using more general area monitoring, process information, and 

information characterizing and quantifying the source term.

NIOSH has found no indication that a routine uranium or thorium urinalysis program was in place 

during the Dow Chemical Company’s AEC operational period. No documentation of medical 

surveillance of any kind for the site has been located.
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NIOSH has not located any documentation indicating that Dow conducted a routine air sampling 

program for uranium or thorium during AEC operations. 

6.2 Available Dow Chemical Company External Monitoring Data

NIOSH has located no indication of external dosimetry or other radiation exposure monitoring records 

for the period from January 1, 1947 through December 31, 1957 at Dow Chemical Company. No 

records or documentation of surface-contamination survey results obtained during or associated with 

the AEC research operations have been located.

Minimal information has been located on the materials handled on site. These materials may have 

included phosphatic ores containing natural uranium and its associated daughters and thorium-bearing 

ores, but no documentation providing details on such has been located. Processing information and 

reports on the research conducted allow NIOSH to infer an estimate of the quantities handled; 

however, no information specific to the quantity of these materials that could confirm these estimates

has been located. 

The NOCTS database was reviewed for claimants whose work history included Dow Chemical 

Company during part or all of the covered period (1947-1957). One such claimant was identified. 

The files for this claimant were thoroughly reviewed and no external monitoring data were found.

NIOSH has no record of any medical X-ray occupational exposure information.

7.0 Feasibility of Dose Reconstruction for the Class Evaluated by 

NIOSH

The feasibility determination for the class of employees under evaluation in this report are governed

by both EEOICPA and 42 C.F.R. § 83.13(c)(1). Under that Act and rule, NIOSH must establish 

whether or not it has access to sufficient information either to estimate the maximum radiation dose 

for every type of cancer for which radiation doses are reconstructed that could have been incurred 

under plausible circumstances by any member of the class, or to estimate the radiation doses to

members of the class more precisely than a maximum dose estimate. If NIOSH has access to 

sufficient information for either case, NIOSH would then determine that it would be feasible to 

conduct dose reconstructions.

In determining feasibility, NIOSH begins by evaluating whether current or completed NIOSH dose 

reconstructions demonstrate the feasibility of estimating with sufficient accuracy the potential 

radiation exposures of the class. If the conclusion is one of infeasibility, NIOSH systematically 

evaluates the sufficiency of different types of monitoring data, process and source or source term data, 

which together or individually might assure that NIOSH can estimate either the maximum doses that 

members of the class might have incurred, or more precise quantities that reflect the variability of 

exposures experienced by groups or individual members of the class. This approach is discussed in 

DCAS’s SEC Petition Evaluation Internal Procedures which are available at 

http://www.cdc.gov/niosh/ocas. The next four major subsections of this evaluation report examine:

• The sufficiency and reliability of the available data. (Section 7.1)
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• The feasibility of reconstructing internal radiation doses. (Section 7.2)

• The feasibility of reconstructing external radiation doses. (Section 7.3)

• The bases for petition SEC-00216 as submitted by the petitioner. (Section 7.4)

7.1 Pedigree of Dow Chemical Company Data

This subsection answers questions that need to be asked before performing a feasibility evaluation. 

Data Pedigree addresses the background, history, and origin of the data. It requires looking at site 

methodologies that may have changed over time; primary versus secondary data sources and whether 

they match; and whether data are internally consistent. All these issues form the bedrock of the 

researcher’s confidence and later conclusions about the data’s quality, credibility, reliability, 

representativeness, and sufficiency for determining the feasibility of dose reconstruction. The 

feasibility evaluation presupposes that data pedigree issues have been settled.

7.1.1 Internal Monitoring Data Pedigree Review

As discussed in Section 6.1, NIOSH has not located any documentation indicating the existence of 

routine air sampling or internal monitoring programs for uranium or thorium during the operation of 

the Dow Chemical Company research facility. The statements made by former workers during 

interviews indicate that air sampling, area monitoring, urinalysis, or in vitro monitoring was not 

performed at this facility. Therefore, an internal monitoring data pedigree evaluation is not possible 

for the internal monitoring data type. 

7.1.2 External Monitoring Data Pedigree Review

NIOSH has not located any personnel external dosimetry data for the period under evaluation. 

Therefore, a data sufficiency and pedigree evaluation is not possible for this data type for this period.

7.2 Evaluation of Bounding Internal Radiation Doses at Dow Chemical 

Company

The principal source of internal radiation doses for members of the class under evaluation was the 

natural uranium that Dow was attempting to recover from the phosphatic material derived from 

processing phosphate rock into commercial products (i.e., fertilizer) (Bailes, 1957). The following 

subsections address the ability to bound internal doses, methods for bounding doses, and the 

feasibility of internal dose reconstruction.

7.2.1 Evaluation of Bounding Process-Related Internal Doses

NIOSH interviewed three former workers and researched historical documentation on the research 

operations at Dow Chemical Company. The three former workers were specifically asked about a 

bioassay program associated with the AEC work at Dow and the three were consistent in reporting
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that there was not such a program (Personal Communication, 2014,a,b,c). This is also consistent with 

the lack of information on any bioassay monitoring in documents reviewed by NIOSH.

Dow Chemical Company workers were potentially exposed to acidic solutions containing uranium 

and uranium progeny. NIOSH has found no indications that bioassay measurements were collected 

for the period under evaluation. NIOSH has also been unable to locate any records indicating that 

breathing zone or area air sampling was conducted during any of the Dow Chemical Company

research, pilot operations, or sample analyses activities. Although former workers indicated that it 

was not common practice to enter laboratory space from other operations or areas of the facility, there 

were no physical or administrative access controls that would limit workers from entering these 

spaces, or generate a record of their presence in an area of potential exposure. The labs designated for 

the AEC work were not physically isolated from the rest of the research lab building, and there is no 

information indicating that there were any engineering controls to segregate the HVAC of these labs 

from any other in the building. Thus, NIOSH has no data to determine which employees were likely 

to be exposed.

The following subsections summarize the extent and limitations of information available for 

reconstructing the process-related internal doses of members of the class under evaluation. 

7.2.1.1 Urinalysis Information and Available Data

NIOSH has not found any uranium urinalysis information for Dow Chemical Company workers.

7.2.1.2 Lung Counting Information and Available Data

NIOSH has not found any information regarding lung counting for Dow Chemical Company workers.

7.2.1.3 Other Types of Bioassay

NIOSH has not found any other bioassay information for Dow Chemical Company workers.

7.2.1.4 Airborne Levels

There was some potential for airborne levels of uranium resulting from the chemical processes 

associated with uranium recovery activities at Dow Chemical Company. The physical handling of the 

uranium-bearing phosphatic solutions was generally carried out in hoods, which should have helped to 

contain any airborne radiological materials. Because there are no air monitoring records for the 

breathing zones or for the general laboratory area, NIOSH cannot directly quantify the airborne 

radiological conditions within the labs during the activities associated with uranium recovery. With 

specific information on the uranium concentration in solution and the volume of solution analyzed at 

any given time, NIOSH could estimate the source term available for suspension into the atmosphere 

of the laboratory. However, NIOSH does not have this level of detailed information for any of the 

different processes investigated at Dow Chemical Company. 

7.2.2 Evaluation of Bounding Residual Period Internal Doses

Dow Chemical Company does not have a designated residual period. 
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7.2.3 Methods for Bounding Internal Dose at Dow Chemical Company

NIOSH has determined that the available data are inadequate to reconstruct worker exposures to 

uranium, thorium, and uranium daughter products resulting from wet-chemical separation activities 

and analyses performed during the Dow Chemical Company operational period under evaluation. 

There are no measured air concentration data that can be used to bound radiological internal exposures 

during the operational period. While the materials were primarily handled in solution, there was also 

the likelihood that a relatively small quantity of raw phosphate ore and solid precipitate were handled 

at the site as part of the investigations into uranium recovery. Both the ore and the dried precipitate 

may have been ground to differing specifications to study the effect of particle size and to increase the 

efficiency of uranium recovery. The physical state of the uranium in an acidic solution would have 

limited the distribution of uranium into the air somewhat, but any grinding of phosphate ore or dried 

precipitate cake could have contributed to the airborne spread of uranium. These laboratory-scale 

investigations, as described in the Dow Progress Reports, documented neither the quantity of 

phosphate ore nor the quantity of dried precipitate cake processed for the recovery research. Without 

air monitoring data to represent the air concentrations encountered by the maximally-exposed 

individual, NIOSH cannot presume to know what the bounding condition was at the site. NIOSH 

does not have access to any personal dosimetry records to support bounding assumptions.

7.2.4 Internal Dose Reconstruction Feasibility Conclusion

NIOSH has evaluated the available information on the activities and materials of concern at Dow 

Chemical Company and has determined that there are insufficient data for estimating internal 

exposures.

NIOSH has not found documentation that describes any sampling or bioassay program at Dow 

Chemical Company. NIOSH has insufficient personnel monitoring data to appropriately characterize 

internal radiation intakes during Dow operations.

In addition to the absence of adequate internal dose monitoring criteria and adequate personnel 

monitoring data, NIOSH has not found general area air sampling, breathing zone air sampling, site 

survey, or source term information to allow it to bound potential exposures, or to demonstrate that 

workers were adequately monitored for potential exposures to radioactive materials at Dow during the 

period being evaluated. NIOSH has determined that reconstruction of the total internal doses received 

from exposures to uranium, thorium, and uranium progeny is not feasible using the information 

available to NIOSH for the period under evaluation from October 1, 1947 through June 30, 1957. The 

periods from January 1, 1947 through September 30, 1947, and from July 1, 1957 through December 

31, 1957, have been excluded from the NIOSH-proposed class because covered work was not 

performed during these times.

Although NIOSH found that it is not possible to completely reconstruct internal radiation doses for the 

period from October 1, 1947 through June 30, 1957, NIOSH intends to use any internal monitoring 

data that may become available for an individual claim (and that can be interpreted using existing 

NIOSH dose reconstruction processes or procedures). Dose reconstructions for individuals employed 

at Dow Chemical Company during the period from October 1, 1947 through June 30, 1957, but who 

do not qualify for inclusion in the SEC, may be performed using these data as appropriate.
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7.3 Evaluation of Bounding External Radiation Doses at Dow Chemical 

Company

The principal source of external radiation doses for members of the evaluated class was exposure to 

beta and gamma radiation emanating from uranium-bearing and thorium-bearing materials. The 

following subsections address the ability to bound external doses, methods for bounding doses, and 

the feasibility of external dose reconstruction.

7.3.1 Evaluation of Bounding Process-Related External Doses

NIOSH has not identified any personal dosimetry data, radiation surveys, or general area surveys for 

research activities involving radiological material handling during the operational period at the Dow 

Chemical Company facility. No inventory information or shipping records have been located to 

support any conclusions regarding specific quantities of uranium- or thorium-bearing materials that 

were handled at any given time on the site. 

NIOSH has not identified documentation to define and quantify the total external source term for Dow 

Chemical Company during the period under evaluation. Without additional documentation, NIOSH 

cannot make supported assumptions about the relative amounts of materials that could have been 

encountered at the site during the period of AEC operations. 

7.3.2 Dow Chemical Company Occupational X-Ray Examinations

No site-specific records have been located, documenting whether the employer held any requirement 

for occupational X-ray examinations at the Dow Chemical Company site, either in the claimant 

records or in the SRDB holdings for the Dow site. EEOICPA requires that external dose from 

medical X-ray examinations performed and required as a condition of employment be included in 

dose reconstruction efforts. If there is doubt about where the X-ray exposure occurred, NIOSH 

defaults to assume the dose was received at a covered facility. Per ORAUT-OTIB-0079, Guidance on 

Assigning Occupational X-Ray Dose Under EEOICPA for X-Rays Administered Off Site, NIOSH has 

determined that it is applicable to reconstruct occupational medical X-ray exposures for Dow 

Chemical Company workers during the period from October 1, 1947 through June 30, 1957. 

7.3.3 Methods for Bounding External Dose at Dow Chemical Company

NIOSH has not identified any external monitoring records or personal dosimetry data associated with 

the uranium handling conducted during the period under evaluation. This was a unique project for 

which there were no operational logs, only technical summary descriptions of activities contained in 

topical reports, and no corresponding radiological data. NIOSH has not located any information 

documenting or describing a regular workplace monitoring program. No records of any routine 

monitoring or area survey program have been located. 

NIOSH has determined that it lacks sufficient personnel monitoring data, area monitoring data, or 

source term data needed to bound external photon, beta, or neutron doses that Dow Chemical 

Company workers potentially received from natural uranium, thorium, or uranium progeny. 
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Therefore, NIOSH has not identified a method for bounding external doses at Dow Chemical 

Company for the period from October 1, 1947 through June 30, 1957.

Medical X-ray Dose 

NIOSH will perform reconstruction of medical dose using the claimant-favorable assumptions

described in the Technical Information Bulletin, Dose Reconstruction from Occupational Medical XRay Procedures (ORAUT-OTIB-0006), including assuming posterior-anterior (PA) projection, preand post-employment screening X-rays, and annual X-ray exposures.

7.3.4 External Dose Reconstruction Feasibility Conclusion

NIOSH does not have access to sufficient personnel monitoring, workplace monitoring, or source 

term data to estimate potential external exposures to uranium, thorium, or uranium progeny during the 

period of process investigations at Dow Chemical Company. Therefore, NIOSH finds that it is 

infeasible to completely reconstruct external doses from October 1, 1947 through June 30, 1957, due 

to insufficient monitoring data. The periods from January 1, 1947 through September 30, 1947, and 

from July 1, 1957 through December 31, 1957, have been excluded from the NIOSH-proposed class 

because covered work was not performed during these times.

Although NIOSH found that it is not possible to completely reconstruct external radiation doses for 

the period from October 1, 1947 through June 30, 1957, NIOSH intends to use any external 

monitoring data that may become available for an individual claim (and that can be interpreted using 

existing NIOSH dose reconstruction processes or procedures). Dose reconstructions for individuals 

employed at Dow Chemical Company during the period from October 1, 1947 through June 30, 1957, 

but who do not qualify for inclusion in the SEC, may be performed using these data as appropriate.

7.4 Evaluation of Petition Basis for SEC-00216

The following subsections evaluate the assertions made on behalf of petition SEC-00216 for Dow 

Chemical Company.

7.4.1 Inadequate Records

Assertion: Records and information are inadequate to estimate the radiation doses acquired by 

members of the proposed class of employees with sufficient accuracy.

Response: Neither personnel monitoring nor bioassay data for Dow Chemical Company workers have 

been found. NIOSH has not located air monitoring data or area monitoring data for the site. 

NIOSH’s review indicates that, in the absence of personnel monitoring data, area monitoring data, or 

adequate source term data, it is not possible to bound potential radiation doses received during the 

AWE period under evaluation. In this evaluation report, NIOSH has proposed an SEC class for the 

period from October 1, 1947 through June 30, 1957.
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7.4.2 Surrogate Data

Assertion: Texas City Chemicals was used to perform dose reconstruction for Dow Chemical 

Company employee(s). The data for Texas City Chemicals was from the mid-1950s, but Dow 

Chemical Company began their work in 1947.

Response: The methods used to recover uranium from the phosphatic acid byproduct of the phosphate 

work at Texas City Chemicals were based on the investigations at Dow. The difference in the period 

that the work was performed is minor and not significant to the potential for exposure in this case. 

The evaluation report for Texas City Chemicals was reviewed and it was found that the data being 

applied in the Texas City Chemicals Evaluation Report are surrogate data. The source term for 

operations at Texas City Chemicals comes from phosphate rock from central Florida that reacted with 

sulfuric acid to produce phosphoric acid. The rock contained naturally occurring radioactive material,

primarily uranium and potentially some thorium, plus associated progeny. Dow initiated 

investigations with the phosphatic acid that was produced commercially at other sites. The 

distribution of radionuclides in the phosphatic acid is specific to the process by which it is produced, 

but generally the uranium and thorium tend to favor the acid phase, while radium-226 and polonium210 are retained in the phosphogypsum stream. Since the phosphogypsum was not delivered to Dow, 

these isotopes contributed to exposure at Texas City Chemicals but not at Dow. 

There are uncertainties with chemical recoveries and potential losses of some elements in some of the 

chemical steps; thus, assumptions for isotopic ratios in the production of phosphatic acid have to be 

applied. The concentration of the product (uranium concentrate) at Dow would have varied for each 

of the methods under investigation (though there were not enough runs of each method to establish a 

routine concentration for any particular method). The radioactivity concentrations in Table 5-4 of the 

Texas City Chemicals Evaluation Report could be applied to Dow for investigations of Florida 

phosphates, but not for investigations on phosphates from the western United States. 

7.4.3 DOE Radiological Survey 

Assertion: The question of where the December 8, 1977 “Walnut Creek” radiological survey was 

performed may be important. DOE documents explicitly point out 2800 Mitchell Drive, which could 

not have been the only location of work. At this precise time the EPA was investigating Dow’s 

Midland plant operations and in December 1977, Dow refused to provide access to the plant, setting 

off an aerial surveillance by EPA that was the focus of Dow Chemical Company V. United States.

Response: Please see the response to the facility location issue below in Section 7.5. The facility 

designation is indicative of the conflation of these two facilities in the available documentation. 

However, it seems clear, based on the investigations of the petition representative and NIOSH, that the 

radiological research operations being evaluated were conducted at the Pittsburg, California location. 

The DOE survey was conducted based on consultation with the Radiation Safety Officer (RSO) at the 

time. This RSO also happened to have been directly involved with the AEC contract work, and would 

have had personal knowledge of the Research Building facilities used for this research. Since this 

individual identified the work location to the DOE personnel, it is highly improbable that the survey 

was performed in the wrong location. It is much more likely that the administrative mailing address 

was used, incorrectly, to identify the physical location of the survey in the follow-on documentation. 
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The DOE survey was part of the FUSRAP efforts and would have been unrelated to the EPA 

investigation of Dow Midland.

7.5 Other Potential SEC Issues Relevant to the Petition Identified During the 

Evaluation

During the feasibility evaluation for SEC-00216, a number of issues were identified that needed 

further analysis and resolution. The issues and their current status are:

• ISSUE: The designation for this facility by the Office of Environment, Health, Safety and Security 

indicates the location as Walnut Creek, California. The “Also Known As” section lists Pittsburg, 

California. These are two physical locations approximately 13 miles (direct line) separating them. 

The names and locations have been used interchangeably in the documentation. 

RESPONSE: The Pittsburg location is currently a manufacturing facility and employs over 300 

people. The Walnut Creek location still exists as a DOE genomic facility. 

A memo, documenting a DOE survey (Bauer, 1977) refers to Walnut Creek, but identifies four 

rooms in the Research Building. The FUSRAP Considered Sites listing lists the 2800 Mitchell Dr. 

address for Walnut Creek. During interviews with former workers, information was given that 

this Walnut Creek location was built after the AEC uranium recovery work had ended at Dow. 

NIOSH investigated and located additional information indicating that the Walnut Creek facility 

was not built until 1961, after the covered period of AEC operations. The Elimination/Site 

Summary Report (Aerospace, 1987, PDF p. 5) refers to the DOE survey as a basis for removing 

Walnut Creek from FUSRAP consideration. DOE identifies the building in FUSRAP references

as ‘Walnut Creek’, but the letter to Dow in 1987 notifying them they were not a FUSRAP site was 

sent to the Environmental Control Dept. in Pittsburg, California. Other letters to Dow also bear a 

PO Box address in Pittsburg, California. NIOSH considered all of this information and concludes 

that all AEC-contracted activities occurred at the Dow-Pittsburg location. 

• ISSUE: There is no mention of any dosimetry or monitoring program for the Dow facility in 

reports or correspondence currently available to NIOSH. 

RESPONSE: NIOSH has not located any reference to a monitoring program. Requests for any 

records or evidence of a monitoring program at Dow Chemical Company were made to both Dow 

Chemical Company in Pittsburg and Landauer Inc. Landauer reported they did not locate any 

evidence that they or their affiliates had provided film badge services to Dow’s California

operations during the period from 1947 to 1957. 

NIOSH’s interviews included a focus on any monitoring programs or efforts. One interviewee 

reported only vague memories of wearing a film badge, but included the caveat that such 

monitoring was unlikely to be productive, given the nature of the materials investigated and the 

lack of external radiation hazard. NIOSH agrees that it is likely Dow did not perform personnel 

dosimetry monitoring.
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• ISSUE: To date, no actual documentation of the radiological source term experimented with at 

Dow Chemical Company has been identified. The contractual agreements spoke to investigations 

on the extraction of uranium from phosphate ores, yet the FUSRAP elimination description of 

work at the site alluded to thorium-bearing ores. There may have been work with raw-uranium 

ores as well.

RESPONSE: All of the topical reports and other documentation reviewed for Dow Chemical 

Company indicate that work was with phosphoric-acid solutions that were provided from various 

commercial phosphate facilities. No indications of the delivery of actual ores at the Dow site were 

found. Interviews with former employees also indicated that Dow’s laboratory research work 

focused on uranium-bearing solutions. There were no indications found of any effort to 

investigate thorium recovery at Dow Chemical Company, nor were there any reports located that 

had indications of other work specifically related to thorium-bearing ores. 

NIOSH also attempted to locate information related to the possibility of work with African ores. 

Reports of work on uranium from miscellaneous African MgX ore seem to be related to work in 

South Africa on a project to introduce uranium recovery by ion exchange in gold mills. This work 

was presumably under the Dow contract and at least one Dow employee may have received 

exposure at the South African mills, but this project would not likely have introduced African ores 

to the Dow Chemical Company site.

• ISSUE: Several references to pilot plant operations have occurred throughout the evaluation of 

Dow Chemical Company research activities. The nature of these operations and the exposure 

arising from these activities to Dow personnel is not well understood. Some indications are that 

there were significant pilot-plant operations and source term that may have generated exposure 

potential onsite, while other references imply that the pilot-plant activities were on a laboratoryscale with an industrial-scale pilot plant located at other locations.

RESPONSE: Section 5.1 of this report details various investigations and research activities 

conducted at Dow Chemical Company. As Dow worked to develop and assess the various 

methods to recover uranium from phosphatic acids, the laboratory results progressed from ‘benchtop’ investigations to pilot-plant studies. Knowledge of the nature and location of these pilot-plant 

operations is vital to the understanding of the radiation exposure hazard delivered by these 

operations to the Dow Chemical Company employees. NIOSH has attempted to document, as 

clearly as possible, the processes that did in fact proceed to the pilot-plant stage of development 

and the scale of those pilot-plant activities. NIOSH concludes that there were small-scale to midscale pilot-plant activities at the Dow Chemical Company location, with large-scale pilot plants 

having been built and run at remote locations, closer to the sources of the phosphate rock. Dow 

Chemical Company engineers were sometimes deployed to assist in establishing and operating 

pilot plants at these remote sites.

7.6 Summary of Feasibility Findings for Petition SEC-00216

This report evaluates the feasibility for completing dose reconstructions for employees at Dow 

Chemical Company from January 1, 1947 through December 31, 1957. NIOSH found that the 

available monitoring records, process descriptions and source term data available are not sufficient to 
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complete dose reconstructions for the evaluated class of employees. Although NIOSH did evaluate 

the entire period from January 1, 1947 through December 31, 1957, the periods from January 1, 1947 

through September 30, 1947, and from July 1, 1957 through December 31, 1957, have been excluded 

from the NIOSH-proposed class because covered work was not performed during these times.

Table 7-1 summarizes the results of the feasibility findings at Dow Chemical Company for each 

exposure source during the time period from October 1, 1947 through June 30, 1957.

Table 7-1: Summary of Feasibility Findings for SEC-00216

October 1, 1947 through June 30, 1957

Source of Exposure Reconstruction Feasible Reconstruction Not Feasible

Internal X

 - Uranium X

External X

 - Gamma X

 - Beta X

 - Neutron X

 - Occupational Medical X-ray X

As of January 7, 2015, a total of 1 claim has been submitted to NIOSH for an individual who worked 

at Dow Chemical Company during the period under evaluation in this report. Dose reconstructions 

have been completed for 1 individual (100%).

Although NIOSH found that it is not possible to completely reconstruct radiation doses for the 

proposed class, NIOSH intends to use any internal and external monitoring data that may become 

available for an individual claim (and that can be interpreted using existing NIOSH dose 

reconstruction processes or procedures). Therefore, dose reconstructions for individuals employed at 

Dow Chemical Company during the period from October 1, 1947 through June 30, 1957, but who do 

not qualify for inclusion in the SEC, may be performed using these data as appropriate.

8.0 Evaluation of Health Endangerment for Petition SEC-00216

The health endangerment determination for the class of employees covered by this evaluation report is 

governed by both EEOICPA and 42 C.F.R. § 83.13(c)(3). Under these requirements, if it is not 

feasible to estimate with sufficient accuracy radiation doses for members of the class, NIOSH must 

also determine that there is a reasonable likelihood that such radiation doses may have endangered the 

health of members of the class. Section 83.13 requires NIOSH to assume that any duration of 

unprotected exposure may have endangered the health of members of a class when it has been 

established that the class may have been exposed to radiation during a discrete incident likely to have 

involved levels of exposure similarly high to those occurring during nuclear criticality incidents. If 

the occurrence of such an exceptionally high-level exposure has not been established, then NIOSH is 

required to specify that health was endangered for those workers who were employed for a number of 

work days aggregating at least 250 work days within the parameters established for the class or in 

combination with work days within the parameters established for one or more other classes of 

employees in the SEC.
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NIOSH’s evaluation determined that it is not feasible to estimate radiation dose for members of the 

NIOSH-evaluated class for the time period from October 1, 1947 through June 30, 1957, with 

sufficient accuracy based on the sum of information available from available resources. Therefore, 

the resulting NIOSH-proposed SEC class must include a minimum required employment period as a 

basis for specifying that health was endangered. Although NIOSH did evaluate the entire period from 

January 1, 1947 through December 31, 1957, the periods from January 1, 1947 through September 30, 

1947, and from July 1, 1957 through December 31, 1957, have been excluded from the NIOSHproposed class because covered work was not performed during these times.

9.0 Class Conclusion for Petition SEC-00216

Based on its full research of the class under evaluation, NIOSH has defined a single class of 

employees for which NIOSH cannot estimate radiation doses with sufficient accuracy. The NIOSHproposed class to be added to the SEC includes all Atomic Weapons Employer employees who 

worked for Dow Chemical Company in Pittsburg, California, from October 1, 1947 through June 30, 

1957, for a number of work days aggregating at least 250 work days, occurring either solely under this 

employment or in combination with work days within the parameters established for one or more 

other classes of employees included in the Special Exposure Cohort. 

As stated in Section 3.3 of this report, the NIOSH-proposed class was modified from the NIOSHevaluated class because during its evaluation NIOSH found documentation regarding the start and end 

dates for the AEC work at Dow Chemical Company. The initiation of the contract with AEC began 

on October 1, 1947, while the contract was completed June 30, 1957 (Contract AT-30-1-GEN-236;

Johnson, 1957). Thus, the periods from January 1, 1947 through September 30, 1947, and from July 

1, 1957 through December 31, 1957, have been excluded from the NIOSH-proposed class because 

covered work was not performed during these times.

NIOSH has carefully reviewed all material sent in by the petitioner, including the specific assertions 

stated in the petition, and has responded herein (see Section 7.4). NIOSH has also reviewed available 

technical resources and many other references, including the Site Research Database (SRDB), for 

information relevant to SEC-00216. In addition, NIOSH reviewed its NOCTS dose reconstruction 

database to identify EEOICPA-related dose reconstructions that might provide information relevant to 

the petition evaluation.

These actions are based on existing, approved NIOSH processes used in dose reconstruction for 

claims under EEOICPA. NIOSH’s guiding principle in conducting these dose reconstructions is to 

ensure that the assumptions used are fair, consistent, and well-grounded in the best available science. 

Simultaneously, uncertainties in the science and data must be handled to the advantage, rather than to 

the detriment, of the petitioners. When adequate personal dose monitoring information is not 

available, or is very limited, NIOSH may use the highest reasonably possible radiation dose, based on 

reliable science, documented experience, and relevant data to determine the feasibility of 

reconstructing the dose of an SEC petition class. NIOSH contends that it has complied with these 

standards of performance in determining the feasibility or infeasibility of reconstructing dose for the 

class under evaluation.
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10.0 References

42 C.F.R. pt. 81, Guidelines for Determining the Probability of Causation Under the Energy 

Employees Occupational Illness Compensation Program Act of 2000; Final Rule, Federal 

Register/Vol. 67, No. 85/Thursday, p. 22,296; May 2, 2002; SRDB Ref ID: 19391

42 C.F.R. pt. 82, Methods for Radiation Dose Reconstruction Under the Energy Employees 

Occupational Illness Compensation Program Act of 2000; Final Rule; May 2, 2002; SRDB Ref ID: 

19392

42 C.F.R. pt. 83, Procedures for Designating Classes of Employees as Members of the Special 

Exposure Cohort Under the Energy Employees Occupational Illness Compensation Program Act of 

2000; Final Rule; May 28, 2004; SRDB Ref ID: 22001

42 U.S.C. §§ 7384-7385 [EEOICPA], Energy Employees Occupational Illness Compensation 

Program Act of 2000, as amended

Aerospace, 1987, Final Elimination Report and Site Summaries-Dow Chemical Company, Walnut 

Creek, California; The Aerospace Corporation; July 28, 1987; SRDB Ref ID: 14538, PDF pp. 4-6

Affidavit, 2014, Affidavit from Survivor; June 30, 2014; DSA Ref ID: 120083, PDF pp. 2-3

Bailes, Feb1949, Progress Report for January 1949, DOW-11; R. H. Bailes; February 7, 1949; SRDB 

Ref ID: ECI 137964

Bailes, Mar1949, Progress Report for February 1949, DOW-12; R. H. Bailes; March 10, 1949; 

SRDB Ref ID: ECI 137966

Bailes, Jul1949, Progress Report for July 1949, DOW-17; R. H. Bailes; July 28, 1949; SRDB Ref ID: 

ECI 137973

Bailes, Aug1949, Progress Report for August 1949, DOW-18; R. H. Bailes; August 30, 1949; SRDB 

Ref ID: ECI 137974

Bailes, Nov1949, Progress Report for November 1949, DOW-21; R. H. Bailes; November 30, 1949; 

SRDB Ref ID: ECI 137977

Bailes, 1951, Recovery of Uranium and Vanadium from Phosphoric Acid Solution by Ion Exchange, 

Paper No. 1; R. H. Bailes; March 22, 1951; SRDB Ref ID: 13579, PDF pp. 4-51

Bailes, Nov1955, Progress Report for September-October 1955, DOW-136; R. H. Bailes; November 

1, 1955; SRDB Ref ID: ECI 137980
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Bailes, 1957, Topical Report Dow-162; R. H. Bailes; September 30, 1957; SRDB Ref ID: 79265

Bauer, 1977, Correspondence regarding a December 1977 Survey of the Dow Facility; Robert H. 

Bauer; December 20, 1977; SRDB Ref ID: 61493

Burnett, 1995, Microbiology and Radiochemistry of Phosphogypsum, Final Report; William C. 

Burnett, James B. Cowart, and Paul LaRock; May 1995; SRDB Ref ID: 30136

Contract AT-30-1-GEN-236, Contract for Studies and Investigation between the United States and 

Dow Chemical Company, select pages; effective October 1, 1947; SRDB Ref ID: 16437

DCAS-PR-004, Internal Procedures for the Evaluation of Special Exposure Cohort Petitions, Rev. 1, 

National Institute for Occupational Safety and Health (NIOSH); Cincinnati, Ohio; April 15, 2011; 

SRDB Ref ID: 94768

DCAS-TKBS-0002, Technical Basis Document for Atomic Energy Operations at Blockson Chemical 

Company, Joliet, Illinois, Rev. 03; National Institute for Occupational Safety and Health (NIOSH); 

Cincinnati, Ohio; November 21, 2007; SRDB Ref ID: 91205

DOE, unknown, Formerly Utilized Sites Remedial Action Program-Elimination Report for Dow 

Chemical Company, Walnut Creek, California; Department of Energy (DOE); unknown date; SRDB 

Ref ID: 14538, PDF pp. 10-15

Form B, 2014, Special Exposure Cohort Petition-Form B; June 11, 2014; DSA Ref ID: 120003

Greek, 1957, Uranium Recovery from Wet Process Phosphoric Acid; Bruce Greek (editor), Otis W. 

Allen, and Donald E. Tynan; Industrial and Engineering Chemistry; April 1957; SRDB Ref ID: 

35734

Guimond, 1975, Radioactivity Distribution in Phosphate Products, By-Products, Effluents, and 

Wastes; Richard J. Guimond and Samuel T. Windham; August 1975; SRDB Ref ID: 13366

Johnson, 1957, Conclusion of Dow Chemical Company Research Work, correspondence to the Dow 

Research Department; Jesse C. Johnson; July 9, 1957; SRDB Ref ID: 61492

Magner, 1957, Direct Solvent Leaching of Uranium Ores with Alkyl Phosphates, DOW-156; J. E. 

Magner; May 1, 1957; SRDB Ref ID: ECI 137965

ORAUT-OTIB-0004, Estimating the Maximum Plausible Dose to Workers at Atomic Weapons 

Employer Facilities, Rev. 03 PC-2; ORAU Team Dose Reconstruction Project for NIOSH; December 

6, 2006; SRDB Ref ID: 36191
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ORAUT-OTIB-0006, Dose Reconstruction from Occupational Medical X-Ray Procedures, Rev. 4; 

ORAU Team Dose Reconstruction Project for NIOSH; effective June 20, 2011; SRDB Ref ID: 98147

ORAUT-OTIB-0024, Estimation of Neutron Dose Rates from Alpha-Neutron Reactions in Uranium 

and Thorium Compounds, Rev.00; ORAU Team Dose Reconstruction Project for NIOSH; effective 

April 7, 2005; SRDB Ref ID: 19445

ORAUT-OTIB-0079, Guidance on Assigning Occupational X-Ray Dose Under EEOICPA for X-Rays 

Administered Off Site, Rev. 00; ORAU Team Dose Reconstruction Project for NIOSH; effective 

January 3, 2011; SRDB Ref ID: 89563

Personal Communication, 2014a, Personal Communication with a Former Dow Chemical Company 

Employee; Telephone Interview by ORAU Team and NIOSH; August 29, 2014; SRDB Ref ID: 

135915

Personal Communication, 2014b, Personal Communication with a Former Dow Chemical Company 

Employee; Telephone Interview by ORAU Team and NIOSH; September 2, 2014; SRDB Ref ID: 

135930

Personal Communication, 2014c, Personal Communication with a Former Dow Chemical Company 

Employee; Telephone Interview by ORAU Team and NIOSH; September 11, 2014; SRDB Ref ID: 

136594

Rad Handbook, 1970, Radiological Health Handbook, Revised Edition; compiled and edited by the 

Bureau of Radiological Health and the Training Institute Environmental Control Administration; 

revised January 1970; SRDB Ref ID: 75017

Roessler, 1979, Uranium and Radium-226 in Florida Phosphate Materials; C. E. Roessler, Z. A. 

Smith, W. E. Bolch, and R. J. Prince; Health Physics (September edition); Received January 24, 1979, 

Accepted February 13, 1979; SRDB Ref ID: 13364

Stoltz, 1958, Recovery of Uranium from Phosphate Ores; E. M. Stoltz, Jr.; July 24, 1958; SRDB Ref 

ID: 4026

Unknown, post-Nov1980, Authority Review-Gardinier, Inc., Tampa, Florida; author not specified; 

date not specified, but written sometime after November 1980; SRDB Ref ID: 11528, PDF pp. 65-69

Unknown, 2001, Hand-Drawn Organizational Diagram; author not specified; February 9, 2001; 

SRDB Ref ID: 11528, PDF p. 28

Wilkinson, 1976, Uranium Recovery from Wet Process Phosphoric Acid, History and Present Status; 

Corald E. G. Wilkinson; May 17, 1976; SRDB Ref ID: 11528, PDF pp. 8-16
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Attachment One: Data Capture Synopsis

Table A1-1: Summary of Holdings in the SRDB for Dow Chemical Company

Data Capture Information Data Capture Description Completed Uploaded 

into SRDB

Primary Site/Company Name: Dow Chemical 

Company

AWE 1947-1957 

Alternate Site Names: 

Pittsburg, CA 

 

Physical Size of the Site: The site encompasses 

513 acres, of which 472 are wetlands, leaving 

41 acres for operational use. The building 

where the work occurred was 4,200 square feet.

Site Population: The current site population is 

approximately 300. During the covered period 

the site population was approximately 100.

Documented communications with former Dow employees. 

The ORAU Team was informed by the Dow Chemical Corporate Office 

that old records have been retired to the Midland (MI) County Historical 

Society.

10/09/2014 2

State Contacted: California Department of 

Public Health, Radiologic Health Branch

The U.S. Nuclear Regulatory Commission turned over responsibility for 

Dow Chemical Company to the State of California in 1997. A search of the 

California Department of Public Health, Radiologic Health Branch website 

for Dow, Walnut Creek, and Pittsburg did not yield any relevant 

documents. A Public Records Request submitted to the Radiologic Health 

Branch identified no Walnut Creek documents and only sealed source 

inspections dating back to 1977 at the Pittsburg location. As such, no 

records were requested.

11/17/2014 0

DOE Germantown Uranium recovery from phosphoric acid, U-233 processing, and search 

procedures for the DOE Oak Ridge Operations Records Holding Area.

03/07/2011 3

DOE Legacy Management - Grand Junction 

Office

A solvent extraction report, the conclusion of research at Dow, a 

radiological survey and descriptions of radiological conditions and 

problems, and a 1942 Metallurgical Project bulletin.

06/07/2011 6

DOE Legacy Management - MoundView 

(Fernald Holdings, includes Fernald Legal 

Database)

Correspondence from National Lead of Ohio regarding the recovery of 

magnesium from contaminated magnesium fluoride.

02/21/2008 1

DOE Oak Ridge Operations Office FOIA requests and Savannah River Site responses to FOIA requests. 11/09/2007 5

DOE Office of Scientific and Technical 

Information (OSTI)

Progress and technical reports. 12/04/2014 31

Federal Records Center (FRC) - Lee's Summit Film badge reports from 1954 to 1956. 10/16/2008 3
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Table A1-1: Summary of Holdings in the SRDB for Dow Chemical Company

Data Capture Information Data Capture Description Completed Uploaded 

into SRDB

Federal Records Center (FRC) - San Bruno The Lawrence Berkeley National Laboratory isotope receiving log, 1949-

1960.

07/26/2012 1

Florida Institute of Phosphate Research Reports regarding the characterization of and doses from aerosols generated 

by phosphate processing.

10/26/2007 6

General Atomics Reports of no radiation dose received by General Atomics employees who 

visited Dow.

01/10/2006 1

Hanford A 1956 letter granting authority to declassify raw materials program 

documents.

03/20/2013 1

Interlibrary Loan A 1958 report on uranium ore processing. 02/22/2007 1

Internet - Defense Technical Information 

Center (DTIC)

No relevant documents identified. 08/15/2014 0

Internet - DOE Comprehensive Epidemiologic 

Data Resource (CEDR)

No relevant documents identified. 08/15/2014 0

Internet - DOE Legacy Management 

Considered Sites

Elimination of Dow Chemical Walnut Creek from consideration as a 

FUSRAP site.

07/22/2014 1

Internet - DOE National Nuclear Security 

Administration (NNSA) - Nevada Site Office

No relevant documents identified. 08/15/2014 0

Internet - DOE OpenNet Manufacturing statements for weapons production schedule of transfers and 

the June 1953 index to the AEC Fourteenth Semiannual Report to 

Congress.

07/24/2014 3

Internet - DOE OSTI Energy Citations The final report on Contract AT-30-1-GEN-236. 02/17/2010 1

Internet - DOE OSTI Information Bridge A 1950 report on the definition of the roentgen at high gamma energies. 

Dow is included on distribution.

08/16/2012 1

Internet - DOE OSTI SciTech Connect No relevant documents identified. 07/30/2014 0

Internet - Energy Employees Claimant 

Assistance Project (EECAP)

No relevant documents identified. 08/15/2014 0

Internet - Google Lists of nuclear sites and FUSRAP sites, Nuclear News articles, the 

DOE/union data tracking meeting, residual radioactivity reports, an Oak 

Ridge National Laboratory isotopes and radiation technology report, Glenn 

Seaborg's journal, photos of the Walnut Creek site, and the turnover of the 

site from the U.S. Nuclear Regulatory Commission to the State of 

California in 1997.

07/29/2014 15

Internet - Health Physics Journal No relevant documents identified. 08/15/2014 0

Internet - Journal of Occupational and 

Environmental Hygiene

No relevant documents identified. 08/15/2014 0

Internet - National Academies Press (NAP) No relevant documents identified. 07/30/2014 0
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Table A1-1: Summary of Holdings in the SRDB for Dow Chemical Company

Data Capture Information Data Capture Description Completed Uploaded 

into SRDB

Internet - National Institute for Occupational 

Safety and Health (NIOSH)

Reports on residual radioactive and beryllium contamination at atomic 

weapons employer facilities.

08/31/2011 3

Internet - NRC Agencywide Document Access 

and Management (ADAMS) 

Staff evaluations of radiological sites identified in a USA Today article, a 

FOIA for thorium licenses at Dow, a petitioner's motion to transfer 

rulemaking from the NRC to District Court, and a list of FOIA requests 

received by the NRC from 01/01/2005 to 02/08/2008.

03/28/2013 6

Internet - Oak Ridge National Laboratory 

(ORNL) 

A 1953 report on uranium extraction and a 1950 operations report 

mentioning magnesium irradiations to be performed for Dow.

03/09/2012 2

Internet - US Army Corps of Engineers 

(USACE)

No relevant documents identified. 07/30/2014 0

Internet - US Environmental Protection Agency 

NEPIS

No relevant documents identified. 07/30/2014 0

Internet - US Transuranium and Uranium 

Registries

No relevant documents identified. 07/30/2014 0

Midland (MI) County Historical Society Attempts to reach the Midland County Historical Society Archivist are 

continuing.

12/04/2014 0

National Archives and Records Administration 

(NARA) - Atlanta

A report on uranium recovery from phosphoric acid. 07/09/2004 1

National Archives and Records Administration 

(NARA) - College Park

A report on a 1951 thorium meeting at Battelle where Dow's phosphate 

extraction process was discussed.

07/13/2010 1

National Archives and Records Administration 

(NARA) - Kansas City

Dow's contract number AT-30-1-GEN-236, a description of uranium from 

phosphate contracts, and the Certification Docket for Gilman Hall which 

identifies Dow as a California FUSRAP site.

03/30/2005 3

National Institute for Occupational Safety and 

Health (NIOSH)

AEC semiannual reports to Congress, general exposure calculations, a 1948 

waste disposal report, the history of the AEC 1947-1952, and Dow progress 

reports.

09/23/2014 13

Nuclear Regulatory Commission Public 

Document Room

Dow's corporate source material license and associated correspondence, 

compliance inspections, and thorium residue storage.

01/29/2007 19

Oak Ridge National Laboratory (ORNL) An isotopes development newsletter and source and special nuclear 

materials accountability reports referencing Dow inventories.

03/19/2014 7

ORAU Team Documented communications with former Dow employees. 09/02/2014 2

Public Library A 1957 report on recovery of uranium from wet process phosphoric acid. 10/16/2007 1

R. S. Landauer Confirmation that Landauer or its affiliates did not provide film badge 

services to Dow's California operations. 

10/10/2014 1

S. Cohen & Associates (SC&A) Irradiations in Idaho National Laboratory's Materials Testing Reactor and 

interest in recovering plutonium from unirradiated scrap.

04/07/2011 2
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Table A1-1: Summary of Holdings in the SRDB for Dow Chemical Company

Data Capture Information Data Capture Description Completed Uploaded 

into SRDB

Sandia National Laboratory - CA September 1965 film badge results. 03/28/2007 1

Savannah River Site Savannah River Site dosimetry visitors cards, a FOIA request, and a FOIA 

response.

08/26/2008 4

Southern Illinois University, Edwardsville, IL Response to a FOIA for NRC's Dow records, a review of thorium activities 

at the Dow Madison plant, and transcripts of Advisory Board Radiation 

Worker Health meetings. 

11/01/2008 7

Unknown Early AEC monthly progress reports, a Project spreadsheet, identification 

of Dow Walnut Creek as a California FUSRAP site, identification of Dow 

Walnut Creek as a raw materials site, and FUSRAP elimination reports and 

summaries.

09/11/2002 10

Washington University Library A 1951 report on the fluorimetric determination of uranium in phosphoric 

acid.

04/23/2007 1

Total 166

Table A1-2: Database Searches for Dow Chemical Company

Database/Source Keywords Hits Uploaded 

into SRDB

NOTE: Database search terms employed for each of the databases listed below are available in the Excel file called “Data Capture Synopsis for Dow Chemical 

Corporation –Walnut Creek Rev 01.”

Defense Technical Information Center (DTIC)

https://www.dtic.mil/

COMPLETED 08/15/2014

See Note above

12,651 0

DOE CEDR

https://www.orau.gov/cedr

COMPLETED 08/15/2014

See Note above 0 0

DOE Legacy Management Considered Sites

http://www.lm.doe.gov/considered_Sites/

COMPLETED 07/30/2014

See Note above 

119 1

DOE NNSA - Nevada Site Office

www.nv.doe.gov/main/search.htm

COMPLETED 08/15/2014

See Note above 0 0

DOE OpenNet

http://www.osti.gov/opennet/advancedsearch.jsp See Note above 179 6
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Table A1-2: Database Searches for Dow Chemical Company

Database/Source Keywords Hits Uploaded 

into SRDB

COMPLETED 07/30/2014

DOE OSTI SciTech Connect

http://www.osti.gov/scitech

COMPLETED 07/30/2014

See Note above 

174 0

Energy Employees Claimant Assistance Project 

(EECAP)

http://www.eecap.org

COMPLETED 08/15/2014

See Note above 

0 0

Google

http://www.google.com

COMPLETED 07/30/2014

See Note above

4,190,700 21

HP Journal

http://journals.lww.com/healthphysics/pages/default.aspx

COMPLETED 08/15/2014

See Note above

7 0

Journal of Occupational and Environmental Health 

http://www.ijoeh.com/index.php/ijoeh

COMPLETED 08/15/2014

See Note above

6 0

National Academies Press

http://www.nap.edu/

COMPLETED 07/30/2014

See Note above

2 0

NEPIS

http://nepis.epa.gov/

COMPLETED 07/30/2014

See Note above

1,624 0

NRC ADAMS Reading Room

http://www.nrc.gov/reading-rm/adams/webbased.html

COMPLETED 07/30/2014

See Note above

144 0

United States Army Corps of Engineers (USACE)

http://www.usace.army.mil/

COMPLETED 07/30/2014

See Note above

0 0

United States Army Corps of Engineers (USACE) -

Sacramento District

http://www.spk.usace.army.mil/ 

COMPLETED 07/30/2014

See Note above

0 0

United States Army Corps of Engineers (USACE) - See Note above 1 0
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Table A1-2: Database Searches for Dow Chemical Company

Database/Source Keywords Hits Uploaded 

into SRDB

San Francisco District

http://www.spn.usace.army.mil/

COMPLETED 07/30/2014

U.S. Transuranium & Uranium Registries 

http://www.ustur.wsu.edu/

COMPLETED 07/30/2014

See Note above

6 0

Table A1-3: Interlibrary Loan Documents Requested

Document Number Document Title Date 

Requested

Date 

Received

AECU-3071 Recent Developments in the Processing of Uranium Ores and Their 

Significance in the Extractive Metallurgy of Metals

10/22/2014

Table A1-4: OSTI Documents Requested (All OSTI-requested documents are awaiting sensitivity review)

Document Number Document Title Date 

Requested

Date 

Received

DOW-140

Ref ID: 137982

Research Report: Recovery of Uranium from Plateau Ores by Solvent 

Extraction with Di-OPA

10/27/2014 12/03/2014

DOW-146

Ref ID: 137957

Research Report; Entrainment of Solvent in Extraction of Uranium 

from Heavy Slurries

10/27/2014 12/03/2014

AECU-3071

Ref ID: 137954

Recent Developments in the Processing of Uranium Ores and Their 

Significance in the Extractive Metallurgy of Metals

10/27/2014 12/03/2014

DOW-156

Ref ID: 137965

Direct Solvent Leaching of Uranium Ores with Alkyl Phosphates 10/27/2014 12/03/2014

DOW-159

Ref ID: 137968

New Methods for the Production of High-Purity Uranium Salts 10/27/2014 12/03/2014

DOW-8

Ref ID: 137956

Dow Progress Report 8 for October 1948 10/27/2014 12/03/2014

DOW-9

Ref ID: 137961

Dow Progress Report 9 for November 1948 10/27/2014 12/03/2014

DOW-10

Ref ID: 137963

Dow Progress Report 10 for December 1948 10/27/2014 12/03/2014
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Table A1-4: OSTI Documents Requested (All OSTI-requested documents are awaiting sensitivity review)

Document Number Document Title Date 

Requested

Date 

Received

DOW-11

Ref ID: 137964

Dow Progress Report 11 for January 1949 10/27/2014 12/03/2014

DOW-12

Ref ID: 137966

Dow Progress Report 12 for February 1949 10/27/2014 12/03/2014

DOW-13

Ref ID: 137969

Dow Progress Report 13 for March 1949 10/27/2014 12/03/2014

DOW-14

Ref ID: 137970

Dow Progress Report 14 for April 1949 10/27/2014 12/03/2014

DOW-15

Ref ID: 137971

Dow Progress Report 15 for May 1949 10/27/2014 12/03/2014

DOW-16

Ref ID: 137972

Dow Progress Report 16 for June 1949 10/27/2014 12/03/2014

DOW-17

Ref ID: 137973

Dow Progress Report 17 for July 1949 10/27/2014 12/03/2014

DOW-18

Ref ID: 137974

Dow Progress Report 18 for August 1949 10/27/2014 12/03/2014

DOW-19

Ref ID: 137975

Dow Progress Report 19 for September 1949 10/27/2014 12/03/2014

DOW-20

Ref ID: 137976

Dow Progress Report 20 for October 1949 10/27/2014 12/03/2014

DOW-21

Ref ID: 137977

Dow Progress Report 21 for November 1949 10/27/2014 12/03/2014

DOW-22

Ref ID: 137978

Dow Progress Report 22 for December 1949 10/27/2014 12/03/2014

DOW-134

Ref ID: 137979

July-August 1955 Progress Report 10/27/2014 12/03/2014

DOW-136

Ref ID: 137980

September-October 1955 Progress Report 10/27/2014 12/03/2014

DOW-141

Ref ID: 137952

January-February 1956 Progress Report 10/27/2014 12/03/2014

DOW-143

Ref ID: 137953

March -April 1956 Progress Report 10/27/2014 12/03/2014

DOW-145

Ref ID: 137955

May-June 1956 Progress Report 10/27/2014 12/03/2014

DOW-147

Ref ID: 137958

July-August 1956 Progress Report 10/27/2014 12/03/2014
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Table A1-4: OSTI Documents Requested (All OSTI-requested documents are awaiting sensitivity review)

Document Number Document Title Date 

Requested

Date 

Received

DOW-149

Ref ID: 137959

September-October 1956 Progress Report 10/27/2014 12/03/2014

DOW-138

Ref ID: 137981

November-December 1956 Progress Report 10/27/2014 12/03/2014

DOW-152

Ref ID: 137960

November-December 1956 Progress Report 10/27/2014 12/03/2014

DOW-154

Ref ID: 137962

January-February 1957 Progress Report 10/27/2014 12/03/2014

DOW-157

Ref ID: 137967

April 1957 Progress Report 10/27/2014 12/03/2014